polletje wil thee

[polletje 21]

bij doc langs geweest om test voeding e.d. te halen heeft hij me een thee machine aangesmeerd!

 

ik helemaal in mijn nopjes, want heb weer wat te doen.

 

nu kwam ik al een topic tegen met onderstaande tekst van grote W.

 

mij is alleen niet duidelijk of mensen dit doen en wat ze er in gooien.

het leuke is dat ik zo mijn eigen thee kan zetten en een mooie mix kan maken.

mijn vraag is wie er ervaring mee heeft?

 

als mensen het leuk vinden zal ik foto's plaatsen van dat ding en laten zien hoe ik t wil gaan doen

 

ik hoor t wel grts

 

 

 

De heren van KJ hebben weer wat hoor...

 

Een hele sympatieke actie dit maal in samenwerking met een paar growshops. De details zullen we nog nader aankondigen (in deze post, bovenin het topic) maar het komt op het volgende neer:

 

Je kunt GRATIS drie keer een emmertje VERSE compossthee halen bij KJ Products (De volger 7b, De Rijp - NH) of bij een meewerkende growshop (adressen gaan we nog bekend maken). KJ zet op locatie compostthee machines neer en verstrekt de ingrediënten voor het maken van verse thee. Er wordt op locatie dus verse thee gebrouwen.

 

In Amerika is het al heel populair om het via de shops te verspreiden en daar staan de kwekers met emmertjes en jerrycans in de rij om dit kostelijke nat te bemachtigen.

 

Er is erg veel informatie beschikbaar over compostthee op het internet, lees je gerust eens even in. Binnenkort komen we met wat meer informatie, maar in theorie komt het hier op neer:

 

• Compostthee wordt vers "gebrouwen" van een zorgvuldig samengesteld mengsel rijpe gehumificeerde compost dat schimmeldominant, bacteriedominant of een combinatie van beiden is (afhankelijk van het type plant)
  
• Het is een vers product met zeer beperkt houdbaarheid, vandaar dat het vers wordt gemaakt
  
• Het bevat enorm veel voedingsstoffen die het bodemleven in je medium voeden en op peil brengen
  
• Ook bij minerale voeding wordt compostthee gebruikt als probleemoplosser
  
• Compostthee is een waterige oplossing die gesproeid kan worden of met het water meegegeven
  

 

Je geeft het mee in de groei, zo'n 2-3 keer afhankelijk van hoe lang je groeit uiteraard. Een keer per week tot 10 dagen is ruim voldoende.

 

Wat zijn dan de speciale kwaliteiten van compostthee:

 

• Het bevat veel voedingsstoffen voor planten en voedsel voor micro-organismen
  
• Het stimuleert organismen in de bodem en op het blad die op hun beurt het beschikbaar maken en vasthouden van voedingstoffen bevorderen
  
• Het verhoogt de afbraaksnelheid van organisch materiaal en toxines
  
• Het verbetert de voedingswaarde van consumptieproducten
  
• Het stimuleert kieming en rijping
  
• Het stimuleert wortelontwikkeling
  
• Het werkt versterkend op alle groeiprocessen
  
• Het zorgt voor een verhoogde natuurlijke ziektewering door ondersteuning van het hiervoor verantwoordelijke biologisch leven
  

 

Ik nodig jullie allemaal uit om eens te gaan studeren op compostthee en een emmertje te gaan proberen als het zover is.

 

Met dank aan KJ products voor het mogelijk maken van deze actie!

 

ps... HH growshophouders in den lande, willen jullie nog meedoen aan deze actie? Neem dan even contact op met KJ products (doc kom er maar in! )

[whazzup 165]

heb je je een 40 liter machine laten aansmeren? Daar kun je 6 voetbalvelden mee bemesten!

 

Je kunt hele goede theepakketten kopen, bacteriedominant of schimmeldominant (en die laatste moeten we volgens mij hebben). Hier wat leesvoer

[polletje 21]

ja ach is voor de leuk toch!

 

misschien als ik een leuke mix heb dat ik wat kan uitdelen... jammer dat t niet lang houdbaar is

 

wil nu voor de bloei wat gaan doen dus dacht batguano en vinasse ofzo?

 

ga eerst met mayan en honey doen, de vorige keer lukte niet zo goed en met die kleine klote pompjes loop ik zo te kutten.

gaat ook snel kapot, dit ziet er wel solide uit.

[carpe_diem 31]

heb je je een 40 liter machine laten aansmeren? Daar kun je 6 voetbalvelden mee bemesten!

 

 

 

is dr een guerilla uitvoering ? op solar energie

[whazzup 165]

thee is wel fantastisch voor guelilla, lekker geconcentreerd, en je kunt het ook prima sproeien

[polletje 21]

als iedereen me dan even hun spot verteld, via pm mag, dan gooi ik wat ik over heb wel daar neer.

 

als ik 6 voetbalvelden kan bemesten hou ik zeker de helft over

 

nog iets te lezen

[polletje 21]

quote deed t niet

 

What Is Compost Tea?

The simplest definition of compost tea is: A brewed, water extract of compost.

Properly made compost must be used, so that the compost tea needs no further pathogen reduction. Compost tea production is therefore, a "cold brewing" process, allowing growth of the organisms extracted from the compost.

Only if the process remains aerobic will the complex set of organisms extracted from the compost remain in the tea. The complex set of organisms is needed to establish all of the benefits of a healthy soil food web in soil, potting mix, or on the surfaces of plants. Plant growth is typically improved, although the correct mixes of beneficial organisms need to be matched to the type of plant (see Ingham et al. 1985, other papers by Ingham, and the Soil Biology Primer, 1999).

Compost is the main ingredient in compost tea, but in order to increase organism biomass and activity, other foods are added at the beginning of the brewing period. These ingredients and their effects are discussed later in this book. Many growers have special ingredients they add. New recipes are always being tested with the goal of achieving higher microbial biomass, better plant production, better soil structure, better nutrient cycling and less disease.

As the processes involved in producing compost tea are better defined, the important parameters that result in the growth of certain organisms will be better understood. Different kinds of aerated and non-aerated compost tea will provide the proper biology for different situations and will be ever-more integral parts of sustainable agriculture.

Sustainable farming is possible, if year after year, the soil is improved and productivity increases. While any one plant species is limited by its genetics, matching the plant to the biology in the soil solves production problems. Natural processes improve soil productivity, and in the natural world, plant species change with time. Plant communities shift from bare soil, to weeds, to grasses, shrubs, trees and then old growth forest. The mythology of modern agriculture is that soil productivity is set, and once a field is put into agriculture, productivity has no choice but to go downhill.

Fertilizer sales people have been heard to say that agriculture depletes soil health and results in loss of tilth. Nutrients are mined out of the soil, ultimately leaving a field devoid of life, plants and nutrients, unless fertilizers are added back into the soil, in plant-available forms. Instead of solving the problem, however, addition of high levels of strictly inorganic, soluble, plant-available nutrients has resulted in an enormous problem with water quality. The nutrients added are no longer held in the soil. As a result, excess amounts of inorganic nutrients have to be added. This is so different from a healthy soil, where the soil holds nutrients, thereby "cleaning up" the nutrients from the water moving through the soil.

Clean water comes out of healthy soil. Why is water coming from "conventional" agricultural fields laden with excess inorganic N, P, S and other minerals? Or if leaching is not occurring, why are the nutrients lost through gaseous emissions? This is not what happens in natural systems.

Change will occur when sustainable agriculture, not extractive, destructive agriculture, is practiced. Pesticides and inorganic fertilizers are not needed, if soil health is maintained. Tillage needs to be reduced to the minimum possible. Disease and pests are not significant in healthy, sustainable systems. Weeds are really just an indication that the system is not healthy. Nature gives growers clues with respect to what is wrong, if the information is read properly. We just need to learn how to read the information being given to us. We reserve the use of pesticides and other toxic materials to the rare situation when some unusual event occurs that harms the biology that should be present..

 

Only if soil lacks the biology required to convert nutrients from plant-not-available forms to plant available forms would addition of inorganic nutrients result in improved plant growth. If the proper biology is not present, then the soil is sick. Extractive agriculture uses tillage and addition of excessive inorganic nutrients which harm the proper biology. When there was plenty of land for "slash and burn" approaches to farming, and farming was done on small scale areas, the land and the biology could recover between extractive agricultural disturbance events.

But in today's world, land is not allowed to recover between farming events, and therefore the organisms and the foods to feed them have to be added back into the system without the luxury of "downtime" to recover. The lack of proper biology must be dealt with immediately, for without that set of organisms, soil structure, nutrient retention and nutrient cycling cannot happen or are severely restricted, and disease suppression and protection are practically non-existent. Returning the organisms needed to build soil health is required.

People who don't understand soil biology will say that bacteria are always present, at more or less the same numbers. But this is an error based on the methods that have been used. The classical medical way of looking at disease-causing organisms was applied to soil, and inappropriate conclusions made. "Plate count" methods assess mainly spores, which are dormant stages of some, but not all, organisms. Spores aren't affected as much as active organisms are by toxic chemicals or tillage. Plate media miss 99.99% or more of the actual species growing and being active in soil. As a result, people relying on plate methods have lead others to extremely mis-informed decisions.

Direct observation methods, especially of active biomass, show that soil biology activity is significantly harmed by pesticides, inorganic fertilizers, tillage and herbicides. The precise impact depends on conditions in the soil. For example, when soil is very dry, and most organisms are inactive, the impacts are limited. But if toxic chemicals are applied when the organisms are actively growing, impacts can be detected.

How rapidly can organisms colonize from another place? Something has to carry bacteria, fungi, protozoa or nematodes from one place to another, and if transportation agents, such as birds, snakes, and spiders, are also dead, how can microbes reach a distant place? Not that many organisms in soil survive a dry, wind-blown transfer. Where, in the chemically impacted agricultural valleys of modern technology, is there even a source of healthy soil for colonization to spread from? The necessary diversity of organisms was killed long ago. The wind can't carry what isn't there.

Therefore, we need to put back the full diversity of bacteria, fungi, protozoa, nematodes and if possible, microarthropods that were killed by toxic chemicals, tillage and lack of foods (organic matter) in the soil need to be put back. Until that happens, people will be forced to use toxic chemicals to attempt to grow plants. Proper nutrition for the plants will be lacking until the organisms that retain nutrients in their biomass are returned to the soil. How do we put back what has been harmed?

It's called compost. Or compost tea, if the source of compost is distant, and transportation costs are too high. Since compost tea extracts the full diversity, and then grows selected beneficials to high numbers, a small amount of good compost can be extended dramatically.

But we need to know how to make compost tea that will contain the full set of organisms needed, at high biomass and activity levels. Depending on what you want to do, choose the method of supplying the organisms your soil needs to become healthy (from the point of view of the plant you want to grow) once again.

Aerated Compost Tea (ACT)

ACT is a water extract of compost, brewed without use of heat, which allows beneficial organisms to grow to high numbers. Foods may or may not be added. If no additional foods are used, organisms are not topically active, and thus less likely to survive transfer to soil or to plant surfaces.

Not-Aerated Compost Tea

A water extract, brewed, with or without added foods, but aeration is not provided. If a highly mature compost with few active organisms is used, the organisms will not be highly active and thus not use up oxygen during the brewing. The tea will likely not become anaerobic, but neither will the organisms stick to leaf surfaces, since they are not highly active. More work on production conditions is needed.

Anaerobic Tea

A brewed water-extract but foods are added (or from the compost) to result in organisms multiplying rapidly, such that oxygen use is greater than oxygen diffusion into the water. The oxygen concentration will drop, and if it drops below the threshold of 6 ppm, aerobic fungi, protozoa and nematodes will be lost, replaced by strictly anaerobic bacteria and yeasts.

Manure Tea

Manure is added to water. If no mixing or stirring is used, only soluble nutrients will be extracted and the tea will typically be high in nitrates, salts, phosphorus, and/or potassium. Antibiotics used in the animal feed are soluble and so normally extracted into the water and can cause significant problems for microorganisms in the liquid extract. If the manure tea is mixed or stirred, high numbers of anaerobic bacteria will be extracted, since anaerobic bacteria are not as good at sticking to surfaces as aerobic organisms. Manure tea contains high numbers of ciliates, extremely low fungal biomass, and can have high numbers of nematodes. Human and animal pathogens can abound as well. At the very least, manure tea cannot provide all the benefits possible from compost tea. Once manure is composted, then it should be called compost.

Compost Extract

By running water at significant pressure through compost, the organisms and soluble nutrients can be extracted from the solids, depending on the extraction force applied.

Compost Leachate

Passive movement of water through good compost removes soluble nutrients and a few organisms. Leachate is not necessarily anaerobic, but can be if organisms in the compost are growing rapidly. Phytotoxic compounds can be present and nutrients can be lost if the leachate becomes anaerobic. Soluble nutrients, enzymes and hormones can benefit plant growth, of course, but care is also needed to make sure salts (e.g., nitrates) are not present in the compost, as high levels can "burn" plant surfaces.

Plant (or Fermented) Tea

Fresh plant materials (e.g., nettles, chamomile, marigolds, and horsetail) can be added to water to remove plant juices. Organisms on the surface of the plant material grow on the dead plant tissues and often go anaerobic for a period of time. As the plant material is used up, organisms stop growing, allowing oxygen to diffuse back into the tea. Usually high numbers of ciliates, extremely low fungal biomass, and many bacteria are observed. Plant teas usually do not contain all the organisms in compost tea, nor provide all the benefits possible from compost tea. Anti-microbial agents can be produced, and quite interesting effects have been produced. More work is needed to achieve consistent production.

Bacterial Soups

As with plant tea, mixes of bacterial species can have specific beneficial impacts. Single species of bacteria can produce bio-control effects, except the conditions in which a single species works is quite limited. Addition of these cultures to compost tea can add functions to the tea, however.

Organisms and Food Resources

Bacteria, fungi, protozoa, nematodes, soluble foods and other nutrients need to be extracted from compost during tea brewing. The higher the quality of the compost, the greater will be the number of beneficial species of each group of organisms. Diversity of food resources and nutrients will improve as more kinds of plant materials are used in the composting process.

Additional foods are typically added in compost tea, some to grow the organisms in the tea brew, but others are added to the finished tea, just before application, to enhance the activity of the organisms so they will glue and bind themselves to foliage, for example. Foliar applications require maximum coverage of the leaf surfaces, as well as maximum activity of the beneficial species. Oxygen during the brewing. The tea will likely not become anaerobic, but neither will the organisms stick to leaf surfaces, since they are not highly active. More work on production conditions is needed.

Anaerobic Tea

A brewed water-extract but foods are added (or from the compost) to result in organisms multiplying rapidly, such that oxygen use is greater than oxygen diffusion into the water. The oxygen concentration will drop, and if it drops below the threshold of 6 ppm, aerobic fungi, protozoa and nematodes will be lost, replaced by strictly anaerobic bacteria and yeasts.

Manure Tea

Manure is added to water. If no mixing or stirring is used, only soluble nutrients will be extracted and the tea will typically be high in nitrates, salts, phosphorus, and/or potassium. Antibiotics used in the animal feed are soluble and so normally extracted into the water and can cause significant problems for microorganisms in the liquid extract. If the manure tea is mixed or stirred, high numbers of anaerobic bacteria will be extracted, since anaerobic bacteria are not as good at sticking to surfaces as aerobic organisms. Manure tea contains high numbers of ciliates, extremely low fungal biomass, and can have high numbers of nematodes. Human and animal pathogens can abound as well. At the very least, manure tea cannot provide all the benefits possible from compost tea. Once manure is composted, then it should be called compost.

Compost Extract

By running water at significant pressure through compost, the organisms and soluble nutrients can be extracted from the solids, depending on the extraction force applied.

Compost Leachate

Passive movement of water through good compost removes soluble nutrients and a few organisms. Leachate is not necessarily anaerobic, but can be if organisms in the compost are growing rapidly. Phytotoxic compounds can be present and nutrients can be lost if the leachate becomes anaerobic. Soluble nutrients, enzymes and hormones can benefit plant growth, of course, but care is also needed to make sure salts (e.g., nitrates) are not present in the compost, as high levels can "burn" plant surfaces.

Plant (or Fermented) Tea

Fresh plant materials (e.g., nettles, chamomile, marigolds, and horsetail) can be added to water to remove plant juices. Organisms on the surface of the plant material grow on the dead plant tissues and often go anaerobic for a period of time. As the plant material is used up, organisms stop growing, allowing oxygen to diffuse back into the tea. Usually high numbers of ciliates, extremely low fungal biomass, and many bacteria are observed. Plant teas usually do not contain all the organisms in compost tea, nor provide all the benefits possible from compost tea. Anti-microbial agents can be produced, and quite interesting effects have been produced. More work is needed to achieve consistent production.

Bacterial Soups

As with plant tea, mixes of bacterial species can have specific beneficial impacts. Single species of bacteria can produce bio-control effects, except the conditions in which a single species works is quite limited. Addition of these cultures to compost tea can add functions to the tea, however.

Organisms and Food Resources

Bacteria, fungi, protozoa, nematodes, soluble foods and other nutrients need to be extracted from compost during tea brewing. The higher the quality of the compost, the greater will be the number of beneficial species of each group of organisms. Diversity of food resources and nutrients will improve as more kinds of plant materials are used in the composting process.

Additional foods are typically added in compost tea, some to grow the organisms in the tea brew, but others are added to the finished tea, just before application, to enhance the activity of the organisms so they will glue and bind themselves to foliage, for example. Foliar applications require maximum coverage of the leaf surfaces, as well as maximum activity of the beneficial species.

Compost Quality

Compost quality is critical. Making certain that the compost has the organisms is extremely important. Aerobic compost means a habitat has been maintained that allows the beneficial organisms to out-compete the less or not-beneficial organisms that grow more rapidly in reduced oxygen conditions. The soluble nutrients and foods in aerobic compost help make certain the organisms will grow in the tea brewing process.

Additives of organisms, different kinds of foods, or nutrients can be used to improve conditions for beneficial bacterial and fungal growth in compost, or even in compost tea. These additives need to be checked for pathogens. Care needs to be taken to not add too much food resource. If excess is added, bacterial and fungal growth will result in oxygen consumption to a detrimental level.

Aerobic Conditions

Aerobic conditions maintain the presence and growth of beneficial organisms. If aerobic conditions are lost, and the tea becomes anaerobic or low oxygen concentrations, the aerobic organisms will be lost. If there are few aerobic organisms, then the resulting brew cannot actually be compost tea. The organisms in the compost have been lost, for the most part.

For that reason, anaerobic teas are not called compost teas, as the organisms which cause the beneficial effects desired in compost tea will not be present. Anaerobic teas may do some interesting things, but they cannot provide the benefits discussed below that are possible with aerobic compost teas.

Machine Testing

Tea-brewing machines must be tested to show that adequate biomass of all groups of necessary aerobic organisms were present in the final tea. The testing conditions should use:

1. Either the food resources sold by the tea machine maker, or a standard set of foods, such as 0.01% fish

hydrolysates and 0.01% humic acid (1 gal offish, and 1 gal of humic acid in 100 gal of water),

2. Compost with documented initial biology,

3. Aerated conditions, such that oxygen remains in the aerobic ranges during the tea brew.

The data from these tests (a minimum of three replicated tests) must be available to the buyer, in order that the buyer can assess whether this machine performs as advertised.

To obtain the full benefits possible from compost tea, the brewing process has to be aerobic. The balance of amount and type of foods added determines oxygen demand by the organisms growing on those foods. Testing of the machine must be displayed by the tea machine maker before anyone would consider buying a machine labeled as compost tea maker..

ASK FOR DATA so you don't have to do this testing yourself. You need to know what amount of food to put in the machine as temperatures change through the course of the year.

Anaerobic Conditions

Anaerobic teas are much less clearly defined than for aerobic tea. Sometimes compost tea may become anaerobic for only a few minutes, for a few hours, or sometimes for days or weeks. Brief anaerobic periods may increase diversity, if the aerobic organisms are not destroyed or put-to-sleep. Prolonged anaerobic conditions mean that many organisms will become inactive or die, and that nutrients will be lost.

Anaerobic tea will not replenish the full soil food web, nor can it be a nutrient supplier. Anaerobic teas add only anaerobic bacteria and yeasts. Leaf surfaces are aerobic environments, and anaerobic organisms do not stay active nor will they perform their functions in aerobic environments. An anaerobic tea applied to an aerobic environment may provide a physical barrier, for a short time, but that is the only function it provides from a food web point of view.

Filamentous fungi that build soil structure and hold nutrients are lost, or become dormant, when conditions become anaerobic. Aerobic bacteria that make micro-aggregates go into dormant stages in anaerobic conditions, and therefore soil structure will not be maintained. Protozoa, nematodes and microarthropods die in conditions that rapidly become anaerobic. Nutrient cycling will therefore no longer occur. In anaerobic conditions, nutrients are lost through volatilization, because major nutrients are converted to gaseous forms in reduced oxygen, conditions. When you smell ammonia, rotten egg, vinegar, putrid, or sour smells, pH is dropping, alcohol is being produced, and N, S, and P are lost as gases.

The work Soil Foodweb Inc. Has done was to define production requirements for beneficial, disease-suppressive, nutrient retaining, nutrient cycling, and soil-structure building compost tea. Anaerobic tea production parameters are still largely undefined, leaving us without a working knowledge of how to predict whether the tea will "work", or not.

Human Pathogens

A major concern is the potential for human pathogens to grow in compost tea. This can only be a concern if the compost is not properly made. Elements in the USDA take the view that even with non-manure materials, human beings could still contaminate compost starting materials. Therefore, all compost must be properly treated (heat or worm contact). Even then, certain programs view compost as potentially containing human pathogens, but they lack a realistic understanding of the environment in which we live.

If there are no detectable pathogens in the compost, and conditions during compost tea production are managed to prevent pathogen growth, then the risk involved in pathogens in compost tea are minimal. There would be more probability of a bird infecting your sandwich while it was sitting on a picnic table than having pathogens grow in the aerobically maintained tea.

Therefore, understanding the conditions selecting against pathogen growth in compost tea is vital. These conditions that select AGAINST human pathogen growth are:

1. Maintain aerobic conditions in order to select against pathogens, which are mostly facultative

anaerobes.

2. Make sure a huge diversity of aerobic bacteria and fungi are present, which compete-with

facultative-anaerobe-growth in all conditions in the tea brewer,

3. Make sure no anaerobic bio-films are left in the tea brewer after a tea brew.

Cleaning is an extremely important factor that many do not consider before buying a machine. No one wants to spend hours cleaning a machine. The greater the number of "hidden-from-view" surfaces present, the longer it will take to clean the machine. Don't trust manufacturers to tell you the truth about cleaning issues. Talk to someone who owns the machine, and who tests their tea. They will relate how critical testing and cleaning actually are.

What Growers Need to Know

The point of applying compost tea is to return the biology that should be present, to grow the desired plants with as little effort as possible. There can be no question that presence of beneficial organisms improves plant growth (Ingham et al, 1985, USDA Soil Biology Primer, 1995 and numerous papers on the benefits of biology to plant growth since that time).

Growers need to know:

1. The biology that should be present in their soils and plant surfaces.

2. If they know what should be there, then they can determine what biology is missing from their

soil.

3. What organisms are in the compost. Selection for bacterial or fungal growth can be managed

during the compost tea brewing process by adding appropriate foods.

4. The tea sprayer does not kill the organisms in the tea

5. Delivery of the missing organisms, along with foods, has been successful.

Beneficial bacteria and fungi are needed to immobilize nutrients, to prevent erosion and run-off by gluing and binding soil particles together to form aggregates, to compete with disease organisms for food, to build soil structure and to allow roots of plants to grow deep into soil and find water and nutrients. Protozoa, nematodes and microarthropods consume bacteria and fungi, and thus release nutrients at the place, time and rates that plants require.

A maximum diversity of each of the sets of beneficial organisms is needed in soil and on plant surfaces. Each combination of environmental conditions selects for the activity of at least several hundred species of bacteria and fungi, several tens of species of protozoa, nematodes and microarthropods. There are always organisms performing their function, until the conditions become so extreme that all activity shuts down, such as when soil freezes, or moisture drops very low. Diversity is necessary, and the way to replenish that diversity is by using compost made with a wide range of plant materials, or compost tea, made from properly processed compost.

Even "pest" species should be present, in low numbers and low diversity, because they have a function in soil. Pests are designed to remove stressed plants, for example, and as such, are indicators that the soil food web is not healthy.

There might be a few disease organisms present in soil and compost. What is a disease in one system may be a beneficial organism in another system. Dormant stages of many organisms survive the composting process, but are not active and do not often cause disease.

The ratios of the different groups must be managed to promote the soil conditions that select for the growth of the particular species of plant desired. For more information about the soil food web, check www.soilfoodweb.com for references, textbooks and publications.

Qualitative Assessment of Compost Tea

Perhaps one of the most exciting recent developments by Soil Foodweb Inc is a way that individuals can easily and cheaply assess every batch of tea of the organisms they want to know about. There is set-up required, and some training is needed to do this yourself, so an alternative is to send the samples into the lab or to an SFI advisor. These assays are typically a factor of 10 less than the quantitative assessments.

This method uses simple categories of assessment, from bad, to poor, to adequate, to good, very good and excellent. Enough people are starting to get "better" than excellent levels, so a new category of outstanding will likely be added. The categories are based on the presence and concentration of organisms observed in the sample, but they are not precisely quantified. They are placed in broad categories, but it allows a general assessment of tea quality.

Classes to train to do this work are typically held whenever enough people sign up, or at about one to two month intervals. Please see the SFI web site for dates and locations. And please remember that if you don't wish to do these assays yourself, contact your closest SFI lab (all labs on the SFI homepage, based on location world-wide).

The qualitative assay is $25 for the categorization of tea, $35 for soil or compost. The full-scale, quantitative assessment, necessary to do scientific study, varies between $100 and $275 depending on the number of organisms groups being quantified.

The Habitat Must Select for Beneficials

The habitat in compost and in compost tea needs to select for beneficial organisms and suppress disease organisms. Most plant and human pathogens require reduced oxygen conditions in order to be highly competitive. Since most beneficials require fully aerobic conditions to function, when oxygen becomes limiting, pathogens win in anaerobic, or reduced oxygen, conditions.

The factors that must be considered for making certain the habitat is correct for beneficial organisms are:

1. The foods used in the compost or the compost tea need to be selective for the beneficial

organisms, not the disease organisms (see Recipe section).

2. The proper set of organisms needs to be present for the foods to be consumed, and for processes to

occur.

3. Temperatures between 65 and 85 F in tea, salts within range, nitrates and sulfur less than 3 ppm

and no toxic levels of any material.

With adequate extraction, compost tea will contain what was in the compost. If there are no human pathogens in the compost, then there will be no human pathogens in the compost tea made from that compost. Thus, compost quality is critical when making compost tea. This means we need to have standards for the biology in compost as well as in the compost tea.

Figure 1. A Soil Foodweb Diagram demonstrates the relationships between the sets of organisms (functional groups in boxes) needed in most crop, grassland, and vegetable soils to grow plants without requiring pesticides or inorganic fertilizers.

 

Plant-feeding Nematodes

 

Is Compost Tea A Fertilizer?

Nutrients are removed when crops are harvested. These nutrients need to be replenished or "put back" into the soil. Even better, fertility should increase with time. Soils in natural systems increase in nutrient concentration as succession proceeds, but this doesn't occur in conventional agriculture, because erosion, run-off, leaching and compaction result in loss of nutrients from the soil.

Why does this happen? What changes? The organisms that should hold both soil and nutrients in place are destroyed in conventional agriculture:

1. By tillage, which slices, dices and crushes the organisms,

2. By use of pesticides which kill far more than just the target organism species,

3. By use of high levels of inorganic fertilizers (which are salts, all of them, killing organisms

through osmotic removal of water), and

4. by compaction which changes oxygen content in the soil, resulting in conversion of organisms

metabolism from aerobic to anaerobic species. The problem is, those nutrients will not be held in a biology-poor soil, resulting in nutrient pollution of surface and ground waters, and atmosphere.

Because of all these losses, conventional chemical systems require 150 to 200 pounds - or more! -of N, to be "added back" to the soil each cropping cycle. In sustainable systems, where the biology is managed properly, and holds nutrients, only the nutrients removed through harvest must be replaced. Based on nitrogen (N) content in plant material, for example, only 15 grams of N per ton of plant material is removed. Therefore, in an orchard where perhaps 4 tons of fruit per acre is removed per acre, only 4 times 15, or 60 grams of N per acre is needed to replace that removed by harvest. Why are some conventional orchardists putting 1000 pounds of fertilizer per acre on their orchards each year?

The "worst case scenario" with respect to harvest removal of nutrients is production of silage, where 200 tons of plant material may be removed per acre. At these high rates, 200 times 15, or 3,000 grams of N (3 kg of N) would need to be added back per acre.

Can compost tea supply those needs? The surprising answer to this question is yes. Not in the standard "fertilizer" form (nitrate), however, but as organic N, held by the biology in organic matter and microbial, biological forms.

Most people have been told that compost is not a fertilizer. That statement can only be made if only soluble, inorganic nutrient values are used. The fertilizer industry has pushed to define N as only nitrate, possibly nitrite, and maybe ammonium, the inorganic forms of N. While this is based on the soluble forms of N that most vegetable and row crop plants take up through their roots, it is far from the only source of N in soil.

If the full soil food web is present, then forms of N that are not nitrate, nitrite or ammonium will be cycled into these soluble forms by the organism. And not just N, but any not-soluble form of any nutrient will eventually be converted from its non-soluble form to the plant-available, soluble form by the organisms cycling system in a healthy soil. Phosphorus, for example, is converted from not plant available forms (in rocks, in sand, silt, and clay, in humic materials, in organic matter, in dead plant material) into organism biomass and then be consumed by predators which results in release of plant-available forms of the nutrient.

If the organisms that perform these cycling processes have been destroyed by agricultural "management", then nutrients cannot be processed from not-plant-available forms into plant available forms. Leaching, erosion, and compaction then result in loss of the remaining nutrients from the soil, and plant production will suffer. The engineering and chemical answer is to load more and more soluble, inorganic nutrients into the soil, while bemoaning the fact that water quality suffers. These sciences have ignored the fact that natural systems manage to hold nutrients, manage to produce clean water, and produce higher plant yields than any agricultural system.

Plans for cleaning up nutrients using mechanical filtration systems (requiring engineers to design, build and maintain them), using soil-less mixes have been suggested as solutions to the water quality problem, all the while ignoring that nature has been successfully feeding everyone since life began on this planet. We have all the food we need; it is social systems that prevent people from having food. The human system needs to be fixed, not the plant production system. We need to learn the lessons nature puts in front of us everyday

Nutrient Pools in Compost

Why is it that when you send a sample into a soil chemistry lab, compost will always be reported as being low in nitrogen? First, soil chemistry labs may remove the obvious organic matter as soon as the sample arrives, because their methods cannot extract minerals from large chunks of organic matter. They typically dry the sample and then use extracting agents to remove the soluble forms of the nutrients from the soil solution (soluble pool), or remove the "exchangeable" forms of nutrients from the surfaces of the clays, silts, sands and organic matter.

Does either approach to extracting nutrients assess bacteria? Fungi? Protozoa, nematodes or microarthropods? No. Nutrients in humus are not extracted either. Nor nutrients in parent material. Only the nutrients that are soluble (dissolved in water) or that can be extracted from the SURFACES of sand, silt and clay particles and organic matter are pulled from the soil. The exact value obtained for any nutrient also depends on the extracting agent used. Some extractants pull more nutrients than others, so in order to compare one lab's results with another's, the extractants used must be known..

What test tells you what the plant will take up? Neither soluble nutrient pool concentration nor exchangeable nutrient pool concentrations will tell you what the plant will take up. Water soluble nutrients concentrations (N or P, or S, for examples) just indicate what is dissolved in water, right now. The plant may not be able to take up any of that if osmotic concentration is too high. If salt content is too high, water is held by the salts, and the plant cannot access either nutrients or water.

Figure 2. The three pools of nutrients in soil. The total extractable pool is assessed using very strong extracting agents, while the exchangeable pool uses less and less strong extractants, until the soluble where weak extracting agents are used. In natural soils, it is the bacteria and fungi that make enzymes and organic acids to solubilize nutrients from rocks, organic matter, clay, sand and silt particles, and tie-up those nutrients in their living biomass, as well as organic matter waste products. Nitrogen is not held in rocks, but N-fixing bacteria perform the same function. These bacteria immobilize that fixed N in their biomass. In both cases, predators are required to mineralize these nutrients into inorganic forms the plants require.

Components of Soil Nutrient Pools Tests used for each pool

Biology

Roots

 

Bacteria and Fungi

Grind; Cone. Nitric acid, combustion 10%HC1, H2NO3

Melich III

Bray 2

Arnm. Cl/BaCl

Colwell Olsen, Bray 1 Melich I

Morgan (Reams) 1 M KC1, Universal

Soluble nutrient concentration does not predict what the plant will take up. It does not predict what nutrients will be solubilized in the next instant. To predict what will be made available to plants requires knowledge of what plant material is present as food for the microbes (how active will the bacteria and fungi be?), what population of bacteria and fungi are present that can solubilize nutrients from parent material, from humus and dead plant material, what population of predators of bacteria and fungi are present and how active they are consuming bacteria and fungi, and releasing soluble nutrients.

Consider the following information based on extractions of nutrients from soil. The original soil contained on average only 1.8 ug of phosphate per gram (ppm) of soil. Rock phosphate and compost were added to achieve a value of 75 ppm phosphate, on average. Two weeks later, soil from the same field was sampled using the same methods and phosphate was 200 ppm. Bacteria has decreased slightly, and fungi had increased by nearly 2-fold. Nothing was added to the field in the intervening 2 weeks. No fertilizer, no pesticides, no tillage, no seed, just grass growing in the field.

Where did the "extra" phosphate come from? Did the lab have a problem? "Messed up" in their assessment? Which time?

Think it through. Plants were growing, making exudates, feeding bacteria and fungi in the root system. Phosphate was solubilized from a plant-not-available pool. Organisms solubilize many nutrients. If the organisms are present, and have foods, they will perform nutrient cycling processes.

What then is the chemistry information that we need in order to predict what will become available to plants through the course of a growing season? If we know the extractant methods used (see right hand side of Figure 3), we can properly interpret what part of the nutrient pool is being assessed by any soil chemistry test. If we then know the biology in that soil or compost, the activity of the bacteria and fungi, the activity of the predators, then we can begin to predict the rate at which N, or P, or other nutrients will become available for plant use. Examination of any of the journals in the area of soil ecology, e.g., Applied Soil Ecology, or Soil Biology and Biochemistry, or Biology and Fertility of Soil, will reveal that this area of investigation is beginning to be understood.

The problem in agriculture has not been a lack of nutrients, but a lack of the proper biology to make those nutrients available to plants. The total extractable nutrient level is in excess in most soils examined so far. But the biology has been destroyed.

Similarly, compost contains plant-available (soluble) nutrients, exchangeable nutrients but an even greater pool of plant-not-available nutrients that will only be made available as the bacteria and fungi in the compost solubilize those nutrients, and then protozoa, nematodes and microarthropods release those nutrients from the bacteria and fungi.

Compost contains both excellent biomass of organisms (bacterial and fungal biomass both in excess of 300 micrograms per gram, protozoa in excess of 50,000 individuals per gram, and nematodes in excess of 60 per gram) and high levels of total extractable nutrients (16,000 micrograms of N per gram of compost, 9,000 micrograms of P, and similar levels for most other nutrients).

Compost tea contains soluble nutrients extracted from the compost. Nearly all of the soluble and exchangeable pools will be extracted, plus perhaps 50% of the total pool in compost, based on assessment of the compost after tea production. For example, an assessment performed by the Environmental Analysis Lab at Southern Cross University showed that the three pools (as shown in Fig 2 above) in a good compost contained about 286 micrograms of soluble N per gram dry weight of compost, about 340 ug of exchangeable N, and 17,000 ug of total extractable N per gram of compost.

That means, in a compost tea (2000 L or 500 gal of water using 15 pounds or about 7 kg of compost), approximately 45,500 micrograms of N were released into the 2000 L of water. One application of compost tea would supply a small but significant amount of N. And even more, when soil organic matter is present, and humic materials were added in the compost tea, a continuing supply of N would be provided to the plants through the nutrient cycling processes the biology provides.

Several compost tea applications could supply all the N a crop needed. But even more, a single application of one ton of compost plus compost tea could supply everything a crop needed, from nutrients to disease protection to weed prevention.

Compost contains many years worth of any nutrient. As long as the biology remains un-compromised by toxic chemical additions, the organisms will cycle those nutrients into plant-available forms. This strongly suggests that compost is a fertilizer; an organic fertilizer. Compost tea will contain many, but not all, of the nutrients that were in the compost. Compost quality is critical to understand, in order that we can maximize nutrient concentrations in the tea. Understanding the role of the organisms is all important, therefore.

Natural systems don't require additions of inorganic, soluble (and thus very leachable) forms of nutrients to maintain productivity. The most productive systems on this planet are systems which do not have, and have not ever had, inorganic fertilizer applied.

If we want clean water, we have to get the biology back in our soils. If we want to grow and harvest crops, we have to build soil and fertility with time, not destroy it. The only way to reach these endpoints is to improve the life in the soil.

COMPOST QUALITY IS CRITICAL

Of all the organism groups in soil (Figure 1), how many are in compost? Compost typically contains all the important groups that are in soil, but typically lacks pathogens, if made properly (Fig 3).

Figure 3. The Compost Foodweb. The organisms in compost tea come from the compost. All of the species and many individuals of each species are extracted from the compost, but individuals reproduce based on the habitat present in the tea. If conditions are appropriate for beneficial species to grow, they will out-compete disease organisms. If the habitat in the tea is more conducive to the growth of disease organisms, disease organisms grow. Care in providing the proper conditions are critical.

 

Organisms

Well-made compost will contain, for the most part, only beneficial bacteria or fungi. Think of the bacteria or fungal boxes in the soil food web picture above as having a dotted line down the middle: Half of the species are "good guys" and help your plants grow, while the other half are "bad guys" that decompose plant tissues if growing on plant surface. These "bad guys" bacteria and fungi are selected against in the composting process, whether by high temperature, competition, inhibition or consumption by predators, or by passage through earthworm digestive systems, the result is the same. Pathogens should be inactive and not detectable in well-made compost.

Organism biomass, diversity and growth or activity can be enhanced by adding organisms, different kinds of foods, or nutrients to improve conditions for beneficial bacterial and fungal growth. Check to make sure they are without pathogens, which means documentation of the biology must be given by the seller of the product. Care needs to be taken to not add so much food resource that the growth of bacteria and fungi will consume oxygen to a detrimental level and allow the compost to become anaerobic.

Disturbance

The less disturbed the compost, especially in the maturation phase of composting, the greater the likelihood that compost will contain higher biomass of fungi, and numbers of predators, such as beneficial nematodes, protozoa, and microarthropods. Good aerobic compost should NOT contain root-feeding nematodes, weed seeds, or human pathogens. Good aerobic compost should contain very few plant pathogens.

Of course the need to not disturb compost during the composting process must be balanced with the need for air in the compost. If the bacteria and fungi have gone through their burst of growth early in the composting process, and are truly maturing the pile, then heat will no longer be generated and the pile will cool. If the microbes are still growing and using food resources, the temperature of the pile will not cool.

Often when anaerobic conditions occur, the pile "never cools". If the pile remains at 140 to 150 for months and months, this is a clear indication that the pile is not compost, and should be considered putrefying organic matter (POM).

Do not use putrefied organic matter to make compost tea, and do not expect any of the benefits discussed relative to good compost to occur if POM is used.

Compost should contain a maximum diversity of many types of bacteria, fungi, protozoa, and nematodes. If water movement through the compost is adequate to pull the organisms from the surfaces of the compost, but not crush the organisms, the microbes in the compost will be extracted into the tea solution. Higher quality compost will have a more diverse microbial population, resulting in greater diversity in the compost tea.

Clearly, compost and compost tea become even more critical, as sources of the indigenous beneficials disappear from the landscape.

COMPOST TEA ORGANISMS

The "Good Guys" or beneficial organisms - including bacteria, fungi, protozoa and nematodes - are present in good compost and therefore will be present in compost tea. Species diversity may be as high as 25,000 species to as many as half a million species in a gram of compost or tea. DNA methods for assessing species diversity of bacteria, fungi, protozoa and nematodes will be the way to determine the actual number. Fingerprinting methods sound promising for assessing diversity. Plate count methods are not useful for assessing diversity. Currently, a combination of selective media, enzymes and fingerprinting can serve to determine whether 20 specific beneficial species are present or not. In this way, you can determine whether your tea includes the beneficial organisms that you need. If they are lacking, then you would know to add them back to your compost or compost tea. More advances are forth-coming in this area, however.

Bacteria.

Good compost teas have on the order of a billion bacteria per ml (108 to 109 bacteria per ml), most of which are beneficial to plant growth. Highly aerobic teas can contain even greater numbers, on the order of 1010 to 10n bacteria per ml. Beneficial bacteria compete with disease organisms for food, for space, and for infection sites on plant surfaces.

Since coverage of leaf or root surfaces by the tea organisms is what is important, these numbers mean that 100 times more tea from a bucket method might be needed to achieve the same results as from one of the commercial units that make good compost tea.

Bacteria make glues that hold them strongly on leaf, root or soil surfaces. This is why nutrients held in their biomass don't leach and will not be lost from soil or leaf surfaces. Given this fact, it is thus necessary to apply enough energy to compost to physically pull these organisms from compost particles into the tea. Some of the initial testing with the Microb-Brewer was conducted to determine the strength of the vortex in the liquid that would remove by not destroy organisms. If too much force is applied, the organisms will be killed by impact on the surfaces of the brewer. This type of testing must be performed with other machines, to make certain the physical blending performed does not macerate or disintegrate some of the organisms, but is enough to pull the organisms from the compost.

Once pulled from the compost, the organisms must be able to pass through the mesh of the compost container, and must survive in the tea. If conditions drop below aerobic levels, many of the beneficial bacteria will not be able to grow, and some will be killed or put into dormant condition. If there are no foods to feed the beneficials, they will become dormant in the tea, and not increase in numbers in the tea. The desired conditions in the tea are aerobic, with good levels of foods to grow beneficial organisms.

Figure 4. Fungi (strands), bacteria (tiny dots and rafts of dots), ciliate cysts (large circles) in a compost

tea.

 

How to Measure Bacteria and Fungi

Direct Methods are the best way to assess both active and total bacterial and fungal biomass in any material. The organisms are viewed and counted and there is no question that what is being counted is the organism of interest. There is no requirement to know what food resource is needed to grow the bacteria or fungi, what temperature the organisms grow at, what humidity is required by the different species, etc. As there is with plate count methods

It is impossible for a single set of incubation conditions to meet the growth requirements for all the different species of bacteria or fungi. For example, a plate count assessment cannot enumerate both heat-loving and cold-loving bacteria species, wet-loving and dry-loving bacterial species, species requiring high N and those requiring low N. Direct methods can assess total and active biomass of bacteria or fungi in any kind of material.

No incubation step is required using direct methods. There is no "guess" required with respect to dilution. Samples are finished within several hours of arrival in the lab so if a different dilution is needed, the original sample can be used. The actual sizes of the bacteria and fungi in the sample are measured, so no guesswork about bacterial and fungal biomass occurs with this method.

Plate Methods are best for identifying SPECIFIC species, using selective growth media. When technological methods for performing direct count methods were not particularly reliable, perhaps 20 to 30 years ago, plate counts were used to estimate total or active bacterial or fungal numbers in soil. However, no one particular type of medium can grow all the different bacteria or fungi that occur in any environmental sample, including compost or compost tea. Consider that the microorganisms in soil, or tea, or compost, grow at many, many different temperatures, use many different foods, and a whole range of moistures and humidity's. These variations are not mimicked in nay way by the growth conditions used in a laboratory. In order to understand true diversity in any sample, plate methods would have to use several thousand kinds of food resources, incubated at each temperature, each moisture, each humidity and each oxygen concentration of interest.

In plate counts, ten-fold dilutions are typically prepared and the quantifier has to "guess" which dilutions to plate on the medium chosen. Plates are then incubated at one temperature, one moisture, one humidity, one set of limited carbon, nitrogen, P, K, Fe, Ca, etc. Concentration. The plate that has a "countable" number of colonies, between 30 and 300 per plate, is counted at 1 and 2 weeks, but how many of the total bacteria present were missed? How can you possibly know which ones were active in the conditions of your soil? Microbiology texts discuss problems with plate count methods (i.e., Sylvia et al., 1999). Plate counts always underestimate the number of actual bacteria present, but what is not known is by how much numbers are under-estimated - 2-fold, 10-fold, 1000-fold, or more?

Plate count methods are therefore NOT useful for assessing species diversity, or species richness.

 

Why Are Bacteria Needed in Tea?

Bacteria occupy most of the leaf or root surface and thus are most effective at consuming the food resources that the disease-causing organisms would otherwise consume. Bacteria occupy most of the infection sites, which would otherwise be occupied by the disease-causing organisms. In soil, bacteria have additional functions beyond consuming foods and occupying infection sites, they also retain nutrients (N, P, S, Ca, Fe, etc) in their biomass (given the C:N ratio of bacteria, they cannot mineralize N, they have to be immobilizing N in their biomass - the exception is nitrifying or ammonifying bacteria which use N as electron acceptors or donators, but these are unusual and very special processes which occur in particular conditions in soil). Bacteria also decompose plant-toxic materials and plant residues (especially the simple, easy to use substrates), and build soil aggregate structure. The smallest "building-blocks" of soil structure are built by beneficial bacteria. Without these bacteria, the bricks to make the "soil house" will not occur and further development of soil structure will not happen. Water-holding capacity can never be improved and soil will remain compacted, if the organisms are not present and functioning in soil, or in compost. Bacteria build the bricks that allow passageways for diffusion of oxygen into, and carbon dioxide out of, the soil.

Thus, it is critical to have bacteria in high enough numbers, and with as great a diversity of species as possible, so that some portion of these bacteria can function within existing environmental conditions and suppress various cultivars or races of disease-causing organisms. Most of the bacteria added in the tea will not be the right ones at the moment you add the tea, so they go to sleep in the soil, and wait for the right conditions that will allow them to wake up, suppress their competitors, retain nutrients, decompose residues, and build soil aggregate structure. But of the tens of thousands of species of bacteria added in tea, several hundred will match the growth conditions present at this moment, and suppress disease, retain nutrients, decompose residues and build soil aggregates. What are the names of these bacteria? We don't know. We can't grow them on ANY culture medium; plate count methods cannot be used to assess these organisms.

Do we have to know the names of each of these bacterial species in order to have them work for us? No. Until science develops ways to inexpensively identify them, just get the critters in tea working without worrying about their names. Let plants select the organisms needed. The plant feeds those organisms that prevent diseases around its roots, leaves, stems, etc. The plant feeds bacteria and fungi, so that protozoa and nematodes will have something to eat, and result in nutrients being made available in the form plants require. The plant feeds bacteria and fungi so they will build soil structure, keeping oxygen diffusion flowing smoothly, as well as making the water-holding pores in soil.

Wise agriculturalists will learn to stop killing beneficial organisms with toxic chemicals and let the organisms in soil do the work nature designed them to do.

Fungi.

There should be 2 - 10 micrograms of active fungal biomass per ml, and 5 - 20 ug total fungal biomass per ml in good compost tea. Decent compost, which should contain 150 to 200 ug of total fungal biomass per gram, contains both simple extractable carbon sources (sugars, proteins, amino acids, simple organic acids) as well as more complex fungal foods (complex amino-sugars, complex proteins, hormones, siderophores, complex carbohydrates, phenols, tannins, and humic acids). Simple carbon sources are easier to extract than more complex molecules, but fungi require complex molecules as their food resource.

Energy must be provided during tea-brewing to extract complex molecules. Complex molecules are needed so fungi have something to grow on in the tea. Fungi also have to be extracted from the compost, which means the aggregate structures that fungi form must be broken, and the fungal strands teased free into the tea solution. This is tricky, to provide enough energy to disintegrate aggregates and to break fungal strands, but not destroy them.

Why Are Fungi Needed in Tea?

Just as with bacteria, certain fungi compete extremely well with disease-causing organisms. The foods added to tea should help these fungi. Materials high in inorganic nitrogen are not wise additions to tea, since high nitrogen levels help disease-causing organisms grow rapidly. Fungi and bacteria often compete with each other for food, space, oxygen, water, etc, so a bacterial tea tends to reduce fungal growth and vice versa. Plants generally require either bacterial-dominated, or fungal-dominated soils because the microbes control nutrient cycling and the FORM of the available nutrients. For example, most trees do NOT do well with nitrate. Nitrate/nitrite tends to select for disease conditions along the roots. Thus ammonium, requiring pH levels lower than 7, and supported by the metabolites produced by fungi, is a better choice for trees.

Fungi tend to occupy only 5 - 20% of the leaf surfaces, but appear to be very important for competition with disease-causing organisms. One reason why applying a single bacterial species to control blossom rot doesn't work is because the environmental conditions may not favor the growth or survival of that single species. Or fungal interactions may be more important under those specific conditions. Beneficial fungi may be needed to consume the exudates that plant leaf surfaces, stems, blossoms, etc., produce, so there is no food to allow the disease-causing organisms to germinate and/or grow on the leaf surface. Infection sites on the leaves may need to be occupied by beneficial fungi so that disease-causing organisms cannot infect the plant.

In soil, fungi have additional functions beyond protecting plant surfaces from non-beneficial organism growth, by competing for nutrients, space and occupying infection sites. These additional functions include:

1. Retention of nutrients (N, P, S, Ca, Fe, etc) in fungal biomass (the C:N ratio of fungi means that fungi

cannot possibly be mineralizing N, they have to be immobilizing N in their biomass).

2. Retention of micronutrients in fungal biomass - fungi are the major holders of Ca, at least in soils we

have tested,

3. Decomposition of plant-toxic materials and plant residues (especially more recalcitrant, less easy to use

substrates), and

4. Building soil aggregate structure. The visible aggregates that are seen in soil are built by fungi by

binding together the "bricks" made by bacteria, organic matter, root hairs, fecal pellets provided by soil

arthropods, etc. Without fungi, visible aggregate formation would not occur as often, and further

development of soil structure would not occur. Soil would remain compacted, because fungi build the

hallways and passageways between aggregates that allow oxygen to diffuse into the soil, and carbon

dioxide to diffuse out of the soil.

5. Improvement of water-holding capacity by building structure in soil.

Thus, it is critical to have fungi in high enough biomass and with as great diversity of beneficial species for the plant as possible to be present, so that at least some species of beneficial fungi will be functioning within the existing environmental conditions. It is the fungal biomass that is most rapidly destroyed by continuous plowing. Fungal biomass is typically lacking in any field that has been plowed more than 10 to 15 times. Thus, beneficial fungi are critical components to return to the soil.

Of the thousands of species of fungi added in tea, the conditions in the soil will match the conditions that are best for only a limited set of fungal species to grow and perform their functions. Which set of fungi will this be? What are their names? We don't know. Typically, we can't grow them on ANY culture medium; there is no plate count method that can enumerate them. We can detect their presence using DNA analysis and molecular approaches, but we then cannot match their function to their DNA sequence.

Do we have to know the names of each of these fungal species in order to get them to work for us? Until methods are available to identify them and give them names, that isn't possible. So, just get the full diversity of fungi back and let the exudates plants produce select for desired species. Don't kill beneficial fungi with toxic chemicals, especially fungicides, or too high levels of inorganic fertilizers.

Figure 5. Basidiomycete fungi (dark brown) with clamp connections growing in brown amorphous soil organism matter. Small dots in the picture are bacteria. Magnification is 250 times actual.

 

 

Protozoa.

Three factors are important for protozoan extraction:

1 . Breaking apart aggregates so protozoa can be extracted from these previously protected places.

2. Supplying energy to pull the protozoa off surfaces, but not kill them.

3. Minimizing brewing time during which protozoa are subject to changes in pressure that results

in cytolysis, or breakage, of individuals.

Protozoa eat bacteria, releasing nutrients that stimulate the growth of bacteria, fungi, and plants, if plants are present. So, when scientists say "bacteria mineralize N in soil", what is REALLY happening is that

. , protozoa mineralize N as they consume bacteria.

With time, protozoa will increase in number in the tea, but when brewing times are short, there is no time for reproduction to occur. For example, a 24-hour brew time is not enough time for an increase in numbers, and only the protozoa extracted directly from the compost will be present in the tea. For short-term tea makers, this means use of good compost is critical in order to extract the protozoa from the compost, since growth will not be possible during the extraction time. Teas that are brewed longer can have protozoa grow in the tea. For example, in a three days tea brew cycle, protozoa could multiply, giving a 3 to 6 times increase in numbers.

Flagellates and amoebae do not tolerate reduced oxygen conditions well. If the tea becomes anaerobic at any time, these groups of protozoa will be killed. Thus flagellates and amoebae are good indicators of aerobic conditions - if their numbers are low, anaerobic conditions or extreme mixing pressures are indicated.

Ciliates, on the other hand, tolerate anaerobic conditions, and indeed, apparently prefer to feed on anaerobic bacteria. High ciliate numbers in tea, or soil, or compost are indicative that anaerobic conditions occurred sometime during the production cycle, although conditions may not be anaerobic at the time of sampling. Anaerobic conditions could have occurred in the PAST, and no longer be a problem.

Immature compost most likely will not have a decent set of protozoa, which therefore cannot be extracted into the tea. Compost needs to cool to at least 125° F (50° C) before most protozoa will start to reproduce normally. Thus, a pile should cool at least 1 week, without turning, after falling below 125° F (50° C) to allow the protozoa to grow and reach minimum numbers (20,000 per gram dry weight of compost) throughout the compost pile.

Nematodes.

Like protozoa, nearly all the nematodes in the compost will be extracted in good tea making machines because enough energy is applied to the compost to pull these organisms out of the compost. Dripping water through compost is not adequate for extraction, however. Good compost normally contains fifty to several hundred beneficial nematodes per gram, which can be extracted into the tea. All these nematodes should be beneficial; only poor compost would contain root-feeding nematodes.

Nematodes play a number of different roles in soil, and it is important to recognize that while one group of nematodes is detrimental to plant growth, most nematodes in soil are beneficial for plant growth. There are four major functional groups of nematodes in soil:

• Plant-feeders are the "bad guys", and consume root material, reducing plant growth and yield,

• Bacterial-feeders consume bacteria, releasing N, P, S, etc which are then available for plant

uptake,

• Fungal-feeders consume fungi, releasing N, P, S, etc which are available for plant uptake, and

• Predatory nematodes consume other nematodes and keep the population numbers of the bad

guys, and the good guys, under control. Too many bacterial-feeders could reduce bacterial

populations below the level needed to suppress disease, retain nutrients, decompose residues, or

build soil aggregates. Thus predators are important controls on the foodweb system.

Compost that has reached high enough temperatures for long enough (131F or 55C for three full days in all parts of the pile), or been processed completely by earthworms (surface contact, or passage through the nematode digestive system) will not contain root-feeding nematodes. Care is needed to choose compost that is mature in order to have a good set of beneficial nematodes in the compost. Awareness of post-production contamination is also required.

Beneficial nematodes do not start to grow in a compost pile until after temperature drops back to less than approximately 115° F (45° C). Both predatory and most fungal-feeding nematodes are killed if the pile is turned too often. Thus, the pile has to mature, unturned, at least two to three weeks AFTER temperature has dropped below 115° F (45° C) in order for there to even be a hope that it will contain adequate nematode numbers.

Mycorrhizal fungi

These fungi do not grow hi tea solutions, although spores and hyphae will be extracted into the solution from the compost. The heating process during composting often kills the spores, so although present, they will not be viable. It is usually of some benefit to add an inoculum of mycorrhizal spores to the final tea solution when the tea is to be used for soil drench or root applications. The food resources present in tea may cause mycorrhizal spores to germinate after a few days, but if the germinated spores do not find active roots within 24 to 48 hours of germination, they will die. Therefore, spores should be added to the tea just before application to the crop, not at the beginning of a tea brew.

Species Composition of Bacteria, Fungi, Protozoa and Nematodes

Species diversity in tea is dependent on diversity in the compost. If there is poor diversity in the compost, the tea will not give the benefits that would result with a healthy diversity of species. Healthy compost has between 15,000 to 25,000 species of bacteria per gram (based on DNA sequence more different than the sequence difference between human beings and chimpanzees, for example), but the DNA analysis required to establish the set of species in highly diverse compost versus the number of species in not-highly diverse compost - or compost tea - awaits further work.

In a study using plate methods, performed by the Soil Microbial Biomass Service (SMBS), every morphological type and every species that occurred in compost was found in the compost tea. Some of the bacterial species extracted will grow in the tea solution, provided the correct food resources are added or present. It is unlikely, though, that all the food resources for all bacterial species will be present in even the best compost tea solution. Therefore, this is a selective step. It is important that the food resources in the tea are selected for beneficial species, and not pathogens.

 

Diverse sets of bacterial species will control pathogen growth. Most pathogens cannot compete well with beneficial species. Therefore, by maximizing bacterial and fungal species diversity, selection will be against the growth of pathogenic and pest species.

In the study performed by SMBS. Fungal species and biomass were found in much smaller quantities in the tea than in the compost. Extraction efficiency for fungi was not great using tea-making methods. In addition, the fungi extracted did not grow well in tea because they were shattered and killed by mixing and agitation. All protozoan and nematode species found in the compost were found in the tea (SMBS study, 1993).

Pathogens in Tea

E. Coli is just an indicator of fecal contamination. Over the last century, total coliforms, fecal coliforms, fecal E. Coli, and E. Coli O157 have been used to indicate human health problems with water and soil. Of these groups, which ones are truly of no concern (you have them on your hands, skin surface, any door handle recently opened, in the roots of plants, etc), of some concern, of significant concern and which can kill people?

Total coliforms are found in a wide range of habitats, and are not of concern, except to say that a fecal E. Coli test should be performed. Wash your hands and your food to remove this bacterial load.

Fecal coliforms exist in animal digestive systems (birds, snakes, rabbits, humans, cows, etc), and are important for proper digestion. Fecal coliforms occur wherever people are present, or where animals are housed. For example, benches and door handles can be good reservoirs, since people touch these objects all the time, and sooner or later someone who has not washed their hands after visiting the restroom will leave a load of fecal coliforms on these objects. Instead of vowing never to touch these things again, vow to wash your hands before you eat. These bacteria are secondary invaders, and only people already sick or stressed by something else will succumb to fecal coliforms. Typically, if you have been getting a normal set of coliforms in soil into your food, there is little risk from these organisms. BUT if fecal coliforms are present in food, or a food preparation area, it means some source of contamination is occurring, and should be tracked down and removed.

Fecal E. Coli presence indicates, however, that a problem exists. E. Coli doesn't survive all that well or for that long in aerobic, non-fecal conditions. That's why it is a good indicator of a problem. If fecal E. Coli is surviving, then it is possible that the true human pathogens such as Shigella, Salmonella, Pasteurella, etc are also surviving. If E. Coli can survive, then so too might the true human pathogens.

But listen carefully to what was just written. If E. Coli can be detected, then the true bad guys MIGHT also be present. Fecal E. Coli presence is an indicator that the possibility exists, and that sooner or later, there will be a problem. So, when fecal E. Coli shows up on the selective medium, it is time to start investigating where the contamination is coming from. What is going wrong? Why are cleanliness procedures not taking care of the problem?

Ask for the results of E. Coli testing when you buy compost to put on your vegetables or food crops. If you apply a source of questionable material anytime 120 days before you are going to eat those vegetables without washing them, there's a possibility that E. Coli could still be present, especially if your crop production system does not have adequate aerobic organisms to out-compete the coliforms. But, a good washing will likely take care of the problem, both on your hands and on the surface of the vegetable.

Fresh vegetables sold in containers are the place where problems are likely to occur, because if the vegetables have a high load of contamination, the bacteria have a chance to grow while they are on the shelf, in the package. There is therefore, a much more stringent set of rules for those processes. A less stringent set of rules is required for back-yard gardeners. This then means we need to make sure that local gardening education programs such as Master Gardeners teach this information and keep up with new information over the years.

If contamination in compost is found, an investigation should then occur, to determine where breakdowns in processing are occurring. The questions would be:

1. Are proper temperatures developing during the composting process? Ten to 14 days at 131 degree F or

higher.

2. Is re-contamination of the pile occurring? If material rolls off the pile, and doesn't heat properly, but is

then added back to the pile, contamination can occur, especially if the set of organisms in the compost

was not fully active and functioning.

3. Where is the contamination coming from? Quite often composting operations forget that machinery

that contacts fresh manure will carry the disease organisms into the finished material, if the machinery

isn't cleaned before it is used with finished product. There should be a separate truck or loader used at

the beginning of the process with the raw materials and a different loader or truck for the finished

product, or re-contamination will occur.

The problem needs to be found, fixed and then the piles re-tested for indicator organisms. When buying compost from a commercial source, you should ask for their E. Coli data, to document that they are at least monitoring the pathogen problem. You should probably also ask for a report on the active bacteria and active fungi, because that's part of the protection system as well.

Only one sub-species of E. Coli are truly human pathogens. The people in danger from this sub-species are those with immature or stressed immune systems. If E. Coli O157 is on or in their food, death can be a result. Only fecal material from people or animals sick with this pathogen contains this pathogen, but there can be animals with sub-lethal illness that can spread the pathogen if care is not taken in the processing of the compost. Thus, compost used to make compost tea should be processed correctly and tested to make certain no contamination of the tea is occurring. While most E. Coli contamination will be removed by proper tea aeration, high loads of E. Coli will not be removed. Thus, making sure that the compost is not contaminated is a must.

E. Coli and aerobic conditions. There is some confusion about the habitat that allows E. Coli to grow. No single condition selects against or for E. Coli, or any other human pathogen. Each pathogen has a particular set of conditions within which it does best. Those conditions must be met in order for the disease organism to grow to high enough numbers to cause a problem if ingested by a person.

What are the conditions that select for human pathogen growth in general, and then in particular? All human pathogens grow much better when oxygen is limiting. Just consider the habitat in which E. Coli, Salmonella and Shigella generally grow - inside warm bodies, where oxygen is limiting and there are sufficient food resources, of the right kind. How limiting? In general, below 5.5 to 6 mg oxygen per liter of liquid. But some don't grow until oxygen reaches even lower levels, 4.5 mg, or maybe 5.2 mg.

The "indicator" organism, E. Coli, makes enzymes that are more capable of taking nutrients away from other bacteria when the habitat is oxygen limiting. If E. Coli can grab food away from other organisms, then the other bacteria can't grow, both because of limited oxygen and because they can't get food. Competition is limited andE. Coli flourishes.

Perhaps not adding any of the sugars that E. Coli can use could be one approach, but then the growth of the competing organisms would be limited in aerobic conditions. Not adding sugar is the incorrect choice. Maintain aerobic conditions, allow lots of aerobic organisms to grow. In aerobic conditions, enzymes work better than those of the human pathogens or indicators of potential pathogen growth.

Compost and compost tea need to have BOTH aerobic conditions AND high diversity of active organisms in order to be a habitat that does not allow disease organisms to grow. If the growth of other organisms is suppressed, then E. Coli can grow aerobically. This is why in lab cultures, when we test for E. Coli, the medium contains foods selective for just E. Coli. The medium often contains antibiotics which kill competing bacteria and fungi. The temperature best for E. Coli growth is also maintained in lab culture conditions. A stain is used to select against other organisms, as well as to detect the pH change that occurs when E. Coli grows. But these lab conditions are a far cry from the real world. In healthy soil, compost or compost tea, there are many other organisms, which in aerobic conditions, grab food away from E. Coli, take up the space E. Coli needs to grow, and consume E. Coli.

Table 1. Can Brewing Tea Remove E. Coin Composted manure high in E. Coli but also high in beneficial bacteria and fungi was used as the compost to brew a tea. The aeration and growth of both the beneficial bacteria and the beneficial fungi out-competed E. Coli. The protozoa in the brew also consumed E. Coli (along with other bacteria) to drop E. Coli numbers to less than what is allowed in irrigation water. E. Coli was assessed using Coli-Blue medium, a standard EPA approved method. Results are the mean of three samples.

 

Material Tested Active Bacterial Biomass ^g) Total Bacterial Biomass

(ng) Active Fungal Biomass

0»g) Total Fungal Biomass (ug) E. Coli (# CPU)

Composted Manure (per gram dry material) 10.5 13,455 0.35 0.56 44,000

SD 1.5 2,446 0.29 0.44 0

Comments on manure Low activity using FDA staining, most of the bacteria were growing anaerobically Lots of bacteria present, most of which were anaerobic Highly variable, because such low levels in the anaerobic manure High variation, it's hard to find fungi where there are so few. Really high numbers of E. Coli, anaerobic conditions

Compost Tea (per ml of tea) 18.9 722 1.33 5.28 2.7

SD 1.9 53.5 0.38 2.45 0

Comments on tea Mostly aerobic bacteria Bacterial biomass much reduced Activity within desired range; aerobic Good totals only possible if aerobic Below irrigation water levels foi E. Coli

SD means standard deviation of the sample values, a measure of variation in the results. The variation should be less than 10% of the mean.

In aerobic habitats, with high numbers of beneficial organisms out-competing and consuming the pathogens originally present, E. Coli will not survive, much less grow. Presumably, if these conditions are encouraged, reduction in E. Coli and other human pathogens can be expected. E. Coli does not long survive in aerobic habitats with lots of competitors and consumers present. That fact should be used more extensively in organic production.

Does the above table GUARANTEE that E. Coli has been killed? No. Clearly there are fecal E. Coli left in the tea, but from a regulatory point-of-view, concentration was brought to below the risk level for vegetable production. Growers of fresh vegetables for market need to understand these interactions, to assure safety for their clients. Monitoring and checking the compost is necessary.

Consider these points when trying to determine if compost or tea should be checked:

1. If E. Coli is not present in the compost, there will be no E. Coli in the tea, no matter how much

molasses or sugar is added. (May 2003 BioCycle).

2. If there are low E. Coli numbers in the compost, and if adequate aeration is maintained, E. Coli willnot survive in the tea.

3. If E. Coli is present in the "compost" but too much food was added in the tea and the tea drops into

reduced oxygen concentration zones, then E. Coli MAY be detected, depending on the growth of

competing organisms.

4. If there are high numbers of E. Coli in the compost, it may take more than 24 hours of aeration to reduce E. Coli numbers to below detectable levels.

5. If the tea maker is not cleaned properly, the biofilm will form a habitat for E. Coli to out compete other bacteria and E. Coli will be detected until the machine is cleaned properly.

In another experiment, E. Coli-free compost (documented with "Coli-blue" MPN medium, standard EPA methods) was used to make tea in 5 gal KIS brewers. No matter how much molasses was used (from 0.1% to 5%), along with kelp, E. Coli was not detected in the tea.

If E. Coli were not present in any starting material, and were not present in the tea brewer, then there can be no E. Coli in the compost tea, regardless of whether sugar of any kind was added. This clearly refutes statements that have been made suggesting that if sugar is used, then E. Coli will grow in compost tea.

If the compost used was actually putrefying organic matter, which is a habitat for the growth of human pathogens, and molasses was used in the compost tea, then it cannot be surprising that E. Coli would be detected in the compost tea. But when the tea brew was well-aerated, and conditions were not correct for E. Coli growth, no or very low levels of E. Coli were detected in the compost tea.

Fungal Pathogens.

Normally, aerobic conditions in the compost tea maker, the fact that humic acids and complex food resources select against fungal pathogens, and competition from beneficial organisms prevent the growth of disease-causing organisms, particularly fungi, in well-made compost tea.

Ascari or eggs of helminth worms can be present in compost, but they are rarely small enough to escape the compost bag. Mesh sizes of greater than 30 mesh retains these eggs. They do not survive or grow in water, so if they are extracted into the tea, they do not increase in number. Properly made compost should prevent these from being a concern. If the compost was treated properly to kill E. Coli, then these parasites should be killed as well. Weed seed will not be extracted into compost tea either.

However, if the compost was not properly composted, and if the tea lacks proper aeration, then fungal pathogens can be present and grow in the compost tea. Pathogens may find a perfect home in felt or fabric bags, if they are not washed and cleaned properly from brew to brew. Tea machine makers should test their equipment for these problems and warn customers of these possible situations. In the best of all worlds, the tea machine maker would change the compost bag so their customers would not have to even consider this problem.

Worm compost

Worm compost contains worm castings plus material that did not pass through the worm digestive system, but contacted the outside of the worms. Typically the organisms inside worms add plant growth hormones, enzymes and diversity that are not in as high concentration in thermal compost. If the worms have been mis-treated, these beneficial materials will be lacking from the worm compost. Therefore, worms have to be considered to be very small livestock, and must be managed correctly to obtain maximum benefit.

Maintaining Aerobic Conditions in Teas

How can aerobic conditions be maintained in compost tea, to assure that the beneficial aspects of compost tea will remain intact and not be lost to anaerobic conditions developing?

The following are some ways you can assess anaerobic conditions:

1. Aerate compost tea sufficiently. This information should be determined by the machine

manufacturer.

2. Measure oxygen, or use a tea maker where the amount of compost, food resource and growth of

the organisms at different temperatures and air pressure (elevation) have been studied and the

information on how to alter the food resources or aeration rate is given with the tea brewer.

3. Use your nose to detect bad smells. But production of these gases may not reach a level your nose

can detect unless you accumulate the smells. Fill half a clean plastic bottle with tea, seal, and

incubate overnight at ambient temperature. Open the bottle (carefully!) and smell. If it smells bad, you aren't aerating enough. If the tea smells ok, then there is most likely enough aeration and not too much food in the tea recipe.

If the tea smells bad, then it probably is bad. Put this tea on something that will not be harmed by the toxins potentially present, for example, an area of weeds, an area with known plant diseases, bare soil that needs organic matter. Let the area recover before growing any plant in the area. This typically requires 120 days if the soil is quite poor and does not have an adequate Foodweb. If the food web is in good shape, recovery (E. Coli or other pathogens no longer detectable) can occur within 3 days.

 

 

HOW TO USE COMPOST TEA

 

Every chemical-based pesticide, fumigant, herbicide and fertilizer tested harms or outright kills some part of the beneficial life that exists in soil, even when applied at rates recommended by their manufacturers. Reviews of these effects are in the scientific literature (e.g., see Ingham, 1985). However, less than half of the existing active ingredients used in pesticides have been tested for their effects on soil organisms. This is an oversight that should perhaps be dealt with by a comprehensive government testing program.

Compost teas, correctly made and applied, improve the life in the soil and on plant surfaces. With time and continued use, compost and compost tea of a quality designed to improve the set of organisms relative to the plant species desired, will increase the number of individuals and the species diversity of the communities of leaf, stem, flower, seed-surface and soil microorganisms, and will select against disease-causing or pest organisms. Thus use of compost tea is indicated when the set of organisms in soil or on plant surfaces is below optimal levels for the plant life desired.

Compost and compost tea add a huge diversity of bacteria, fungi, protozoa, and nematodes. Typically, if the compost is well-made, beneficial organisms are present in the compost, not diseases or pests. Thus, making or obtaining good compost is critical.

Standards for compost production and for the biological components of compost relative to the requirements of the plant are given on the SFI website (www.soilfoodweb.com). The beneficial organisms and the soluble foods to feed them must be extracted from the compost and survive in the tea in order to obtain the full benefit of a healthy compost tea.

Potential Benefits of Compost Tea

The whole set of beneficial organisms must be extracted and survive in tea. Soluble foods must be extracted or added to tea so the beneficial organisms can grow. If all these things occur, then the benefits of using compost tea for foliar or root applications can include the following:

1. Pathogens cannot infect the plant tissues because the specific infection sites on the plant surface are

already occupied by beneficial organisms;

2. Disease-causing organisms have no food and cannot grow because the exudates produced by the plant

are used by the beneficial species present on the plant tissues before the disease-causing organisms

arrive;

3. Spaces on the surfaces of plant are physically occupied by beneficial organisms. The pests and

pathogens cannot reach the plant surface, and disease cannot occur;

4. Plants take up nutrients in the tea needed to allow them to resist infection more rapidly because the

beneficial biology influences leaf surface gas concentrations, causing stomates to open sooner and for

a longer time;

5. Food resources in the tea allow beneficial microorganisms to grow, protecting plant surfaces;

6. Nutrients are retained on the leaf surface and become available to the plant with time, improving plant

nutrition and health;

7. Soil structure is improved and more oxygen reaches the root system, preventing toxins from being

produced in the soil, increasing plant health;

8. Water-retention in soil is improved, reducing water use by up to 50% in two years in some cases;

9. Rooting depth of the plants is increased, increasing the nutrients the plant can access;

10. Decomposition of plant materials and toxins is increased;

11. The nutritional quality of plant produce is enhanced;

12. Worker exposure to potentially harmful chemicals is reduced;

13. Chemical-based pesticides, herbicides and fertilizers are no longer used, and beneficial microorganisms

in the ecosystem are no longer killed or harmed;

14. Chemical input and labor costs are reduced;

15. On-farm recycling of waste is enhanced;

16. Landfill space requirements can be reduced;

17. Plant growth can be improved.

 

Not all of these benefits will be observed in every case of tea application, perhaps because the compost did not contain the necessary organisms. The necessary organisms may not have been extracted from the compost, or did not grow in the tea or may have been killed during removal from the compost or during the growth process. Other reasons for lack of the necessary organisms in the tea may be that toxic materials were leached from poor compost, or the compost became anaerobic and killed the aerobes during the brewing cycle, or some other factor was not optimal.

Application of Compost Tea

There are two different, but not mutually exclusive, ways of applying compost tea: as a soil drench, or as a foliar spray.

1) Foliar applications:

a) Apply beneficial organisms to plant aboveground surfaces, so disease-causing organisms

cannot find infection sites or food resources (i.e., pro-biotic approach).

Provide nutrients as a foliar feed.

2) Soil applications:

a) Help develop the biological barrier around roots (i.e., pro-biotic approach),

Provide nutrients for roots to improve plant growth,

c) Improve life in the soil in general, with effects on soil structure, water holding, root

depth,

d) Improve nutrient cycling, nutrient retention and disease-suppressiveness.

Foliar applications

These are applied typically with no dilution, although water is often used as a "carrier". Concentration of organisms in the tea is critical, so careful attention to maintaining that concentration is important. If the tea is diluted, inadequate coverage on leaf surfaces may occur.

If tea is within the desired range indicated on the Soil Foodweb report (see following sections on beneficial organisms in tea), then it can used at 5 gal/ac (50L/HA). If organism numbers are greater than this, then the tea can be used at a lower rate, relative to how much it can be diluted based on getting adequate coverage on the leaf surfaces.

If disease is visible on leaf or blossoms surfaces, then tea should be sprayed directly, with no dilution, on the affected area, without regard to a per acre amount. Drenching the affected plant tissue and immediate surroundings, where the foliar disease organism may have spread, should be performed as rapidly as possible, typically within 24 hours of observing the first evidence of a problem.

Generally on seedlings and small plants, such as tomato seedlings, peppers, basil, etc, five gallons of tea to the acre (50 liters/HA) every one to two weeks through a disease infection period give excellent protection of plant surfaces.

For larger plants, more tea is required because of the greater foliar area to cover. For example, a single 25-foot (8 meter) tall oak tree may require 25 gallons (250 liters) of tea to adequately cover the leaf surfaces. Generally, apply 5 gallons of tea per ac for each 6 feet in height of the plants. Thus, an acre of 25 foot tall trees would require 25 gallons of tea (5 gallons for the 0 to 6 feet height, another 5 for the 6 to 12 foot height, another 5 gal for the 12 to 18 foot height, another 5 gallons for the 18 to 24 foot height, and another 5 gallons for the top foot, or 25 gallons per acre). Most people err on the side of too generous, because as far as we are aware, you do not have to worry about over-application. Under-application can lead to problems if the organisms in the tea are inadequate.

The critical factor with respect to foliar applications is coverage of the leaf surface by the organisms in the tea. One reason coverage is important is that beneficial organisms must consume the leaf surface exudates, leaving no food for the disease-causing organisms so these organisms are unable to germinate or grow. Another reason is that all the infection sites on the leaf need to be occupied by beneficial organisms, so no site allowing infection is left unprotected.

 

Without assessment of leaf coverage at some time during the season, there may be serious problems preventing adequate organisms in the tea (tea quality) or adequate coverage on the leaves (leaf coverage). Testing is necessary. If the leaf is covered adequately by beneficial organisms, there can be no colonization of the plant surface by disease-causing organisms. Does this always work? Given adequate coverage of the plant's surface, the answer is yes.

The plant surface must be assessed for adequate coverage in order to make certain the tea contained the required set of organisms and that these organisms cover the plant surface adequately.

In Recent Experimental Results section, a minimum of 60 - 70% coverage of the leaf surface was required. A minimum of 5% of that coverage had to be beneficial fungal biomass in order to prevent disease from establishing on leaf surfaces.

Pesticide residues in tanks, chlorine in water, too cold water either in the tea brewing or for dilution in the spray tank, application when UV may destroy the organisms, temperatures too hot in the brewing process or too high when spraying, and poor extraction energy are all factors that must be recognized as resulting in poor coverage of organisms on leaf surfaces. Testing is needed.

Tea organisms on the leaf surface can be removed by rain or wind, killed by UV, or pesticide drift, especially if the plant is not supplying adequate food resources.

Figure 6. Compost tea application to vineyard in Monroe, Oregon, as part of the USDA-SARE study on Compost Tea Effects on Mildew andBotrytis awarded to the Sustainable Studies Institute, Eugene, Oregon

 

 

Use of a biological spreader/sticker, such as yucca, pine sap, or simply molasses, can help, but choose a material that does not cause osmotic shock or destroy organisms. As long as the le*af material is adequately covered with beneficial organisms, then the plant surface will remain healthy and disease cannot win in the competition for the leaf surface. How would you know if the organisms are still there? Have a leaf organism assay performed.

If disease appears after tea is used, consider then that something prevented adequate coverage of the leaf surface or killed the organisms before or after they were applied. The disease may have been mis-diagnosed, and what was called a foliar leaf disease was in fact stem rot. The soil needs to have a healthy food web to prevent stem rot and the tea should then be applied to the stem and soil around the plant, not to the leaves. Alternatively, if pesticide residue in the sprayer killed the organisms in the tea, then disease may occur through no fault of the conceptual approach! If a leak in the machine's pump let oil into the tea, organisms will be killed; or if pump pressure was too high or too low.

Leaf samples should be sent for analysis after the first tea spray of each season, so the quality of the tea and coverage of the leaf is assured. As long as the leaf stays adequately covered, no problems have been observed. If tea is applied and plant surface coverage has been shown to be adequate, and still disease takes over, then this is a situation that requires attention because it is unusual (i.e., has not been seen before). The author of this manual would request further interaction on this situation, because it presents a situation that needs to be understood. What allowed diseases to be able to "win" in the competition for the leaf surface and how can we prevent this from occurring again? This situation would present a challenge to our understanding of why compost tea works, and figuring out how to overcome this challenge keeps us on the cutting edge.

Soil applications

The soil needs to be inoculated with the right set of organisms, and the foods for the organisms to consume, in order to keep beneficial organisms functioning through the year.

On a per plant basis, typically 1 liter (0.25 gallons) of tea (water can be used as a carrier if required) is applied per 100-mm (3 inch) tall seedling when planting into the field. The foliage and soil around the plant should be drenched by this application. A one-time application has proven adequate to prevent soil root disease if the soil contained a reasonable food web before tea application.

If the soil does not contain an adequate food web set of organisms, then multiple applications may be needed. For example, in strawberry fields where methyl bromide was injected before planting, 20 liters of tea per acre (5 gallons/ac) were applied at each two week to 1-month interval to maintain soil health. This 5 gal of tea can be added in any amount of non-chlorinated water, as long as the full 5 gal of tea is applied to the 1 acre of area.

An alternative is to apply good compost around the root systems of the plants, so soil drenches of tea may not be necessary. As always, if disease is observed, then a tea application is immediately indicated.

How far does the tea move into the soil? It depends on the soil texture, compaction and the amount of organic matter in the soil. The sandier the soil, the further down the tea, and the organisms in it, will move. The heavier the clay, the more the tea stays at the surface. Organic matter can open up structure in heavy clay, and then the tea, and the organisms, will move deeper. Organic matter usually allows the organisms added in the tea to continue growing, so added benefit is obtained from a single application of tea with greater organic matter in the soil. Compaction of course reduces the ability of water to move through soil, and increases the likelihood that inadequate oxygen is present.

In the greenhouse or nursery or a field where disease has been a problem, the soil should be drenched before planting. In pots, a drench means water should just barely begin to drip from the bottom of the pots. Be careful that the tea does not just run along the inner surface of the pot and out the bottom of the container. In the field, soil should be wetted to the depth of the plant's root system. Once plants are planted, apply tea to the foliage as well as using a soil drench. In situations where disease has been serious, saturate the soil surface, and maintain stem and leaf coverage by tea organisms every week to two weeks to keep the soil and plant healthy. If problems are encountered, feedback is requested, so unusual situations can be explored and solutions found.

Generalized Approaches for Using Compost Tea

How and when do you apply compost tea? It depends on the plant, the soil, the seasonal cycle, and exactly what it is you want to do. A few examples are given below.

Addition of compost in conjunction with compost tea needs to be considered. Properly made, aerobic compost contains an amazing amount of nitrogen (16,000 ug N per gram of compost), phosphorus (23,000 ug/g), sulfur, calcium, and micronutrients.

When assessing the need for compost, determine the amount of compost by considering the amount of N needed to replace the nutrients removed in the crop. The previous crop removed between 50 and 100 pounds of N per acre (residues left in the field). That means 50 to 100 pounds on N must be replaced in the soil. Aerobic compost has a C:N of 20:1 and thus 2 tons up to 4 tons of compost should be adequate to replace the N. P, K, etc. Removed in the crop. Paying attention to just nitrate or ammonium is not going to tell you what N will become available from the organic matter and the organisms also added in the compost. These count as sources of N, if you have adequate biology present. Compost tea will also contribute N, P,K, etc, but not usually enough to do more than give a foliar "shot-in-the-arm".

Figure 7. Asparagus grown with an autumn application of compost (1 ton/HA) and three monthly applications compost tea through the spring growing period. No weeds to speak of were present in the organic area while asparagus could barely be seen for the weeds in the conventional field. The asparagus was on average 5.5 to 6 foot tall in the organic filed, and only 4 to 4.5 feet high in the conventional field. The yield in the organic treatment was double as compared to the conventional asparagus. Richard Prew, Cambridge, New Zealand.

 

Organic, with tea

 

ew weeds, taller plants, no bare groin

Potato

In the fall, after harvest, just before fall rains or snow occur, apply enough compost to improve the soil food web to desired ranges (1 to 5 tons/ac, or 2.5 to 12 tons/HA), but no more than 10 tons to the acre (too much compost in one application will compact and possibly become anaerobic).

Soil chemistry should be assessed, and any nutrient deficiencies should be dealt with by adding fish, kelp or other micronutrients into the compost or compost tea. Making sure the compost or tea brings in the proper biology is also necessary.

Generally 10 tons of compost is much, much more than needed, but in the first year of resuscitating soil after years of methyl bromide applications, it may be necessary to apply as much as 30 tons to the acre. Typically, in soils not destroyed by severe chemical usage, 1 to 5 tones to the acre is reasonable.

If that many tons of good compost are not available, apply compost tea instead. It might be a good idea to apply mulch or ground "compost" material, followed by an application of compost to inoculate the proper biology. Typically 15 to 20 gal of compost tea per acre (150 to 200L/HA) is applied as a soil drench,

If the tea is top quality and contains more than an adequate amount of fungi, then less compost tea might be used. But, if the compost tea lacks fungal biomass, then the amount of tea must be increased to assure adequate fungal application. Without adequate fungi, plant residues may not decompose rapidly. Without adequate fungi, pesticide and inorganic fertilizer applied during the summer may not properly decompose. A good rule-of-thumb is that the residues should be half-gone within a month of harvest, if temperature and moisture have been in reasonable ranges. If the plant residues from harvest are not half-gone within a month, then a second application of compost tea as a soil drench is indicated.

 

In the first spring following conversion to sustainable growing, a second application of compost should be applied, again at 15 to 20 gal/ac (150 to 200 L/HA) compost tea as a soil drench.

If the conversion to sustainable is started in the spring, no guarantees can be given with respect to success in the first crop cycle. It is just too soon to expect, with 100% confidence that all the improvements that the biology can supply will actually occur in the first growing season, when the biology has not had the entire winter, or non-growing season, to establish and start the process of building soil structure.

In the spring, seed pieces should be treated with a surface spray of compost tea. If VAM colonization is not adequate on the root surfaces, add VAM spores to the tea. VAM colonization should be monitored each year in the fall in order to know if VAM spores will be needed.

If potato seed pieces have been treated with fungicide, then the compost tea with VAM spores should be sprayed or dribbled onto the soil below where the seed pieces will be placed. This allows the roots to become colonized with beneficial organisms and VAM as the roots grow out of the seed piece and through the compost tea inoculum.

Figure 8. Applying compost tea with a jet nozzle at Jolly Fanner in New Brunswick, Canada. Almost any nozzle will do for applying tea, as long as the nozzle opening size is larger than 400 micrometers in diameter.

 

At the first true leaf stage, and then again just before blossom and again just after blossom, the plants should be treated with 5 gal/ac (50L/HA) of good, as-fungal-as-possible tea as a foliar application. If the fungal component is too low, then increase the gallons of tea applied to make sure adequate coverage results. Brewing and applying another tea should be considered if fungi are inadequate.

Add foliar nutrients if the plants show any signs of nutritional limitations. Organisms in the tea increase uptake of foliar nutrients. This means the concentration of nutrients applied as inorganic fertilizers can be sharply reduced even in the first year of conversion to biological.

After harvest, begin the cycle again.

Since diseases, root-feeding pests and foliar insects are excluded from these systems through the addition of a healthy food web, rotation of crops will quite quickly no longer be necessary. Nutrient cycling will begin to occur again. Diseases that were enhanced each year in the conventional management system because of developing resistance-to-the-chemicals no longer develop. But consider that diversity is critical to maintain a healthy food web, so variation in the foods going into the compost will continue to be extremely important.

Monitor the soil food web annually in the fall to know what kind of compost is needed to replace the organisms that may have been lost during the crop cycle.

Weather patterns can be strange, and surprises will always be part of the growing system. Monitoring the soil food web is necessary. If plants looked diseased, then additional applications of tea may be needed, either as soil drenches or foliar sprays. In the worst cases, fungicides or insecticides may be required to deal with a plague situation. If used, just remember that some beneficial organisms have been harmed, and need to be replaced or helped to be resuscitated. Use compost or compost tea to do the job of putting back in the biology as well as some foods.

Table 2. Data from Jolly Farmer 2003 Compost Tea Potato Trial, using Russet Burbank cultivar,

Ernest Culberson field agent.

Check

With Compost tea

Differences

 

Total Yield (cwt/ac) Market Yield (cwt/ac) Large size (%) Small size (%)

304 233 10.3

23.4

335 272 16.2 19.0

+ 31 in tea +39 in tea + 5.9 in tea

- 4.4% in tea

Row Crops / Broadacre Crops

Corn, wheat, tomato, lettuce, etc all are treated the same as potato:

1. Fall application of compost (1 to 5 tons.ac) or compost tea (20 gal/ac as soil drench) need to be

made.

2. Monitor VAM colonization in plants needing mycorrhizal colonization (many brassicas are not

mycorrhizal).

3. Monitor residue decomposition.

4. Apply compost or tea (20 gal.ac soil drench) in the spring to replace anything missing in the soil.

5. Apply compost tea to the seed or to the soil in the planting row, with VAM spores and/or humic

acids if needed, to improve VAM colonization.

6. Applications of foliar compost teas (5 gal/ac for each 6 foot height of canopy) should occur at first

true leaf stage, before blossom, and after blossom.

7. If any diseases are scouted, apply the teas ASAP to re-occupy the leaf surfaces so the diseases

cannot win. Along roads, boundaries with neighbors that spray chemicals, and where drift from

toxic areas occurs, extra teas may be required.

8. Monitor leaf surfaces.

9. Check the tea for the beneficial organisms (SFI assays).

As with any system, variation in application times and methods will occur. No matter what sprayer, tea maker or weather condition, checking leaf surfaces, or checking the soil to determine if the biology is present, or checking leaf surfaces to determine coverage, checking to determine if the organisms are growing, or active, can always be done, and give peace-of-mind.

A new approach in field crop or row crop systems is to put a perennial cover crop in the system as has been tried at Washington State University. Green "manure" cover crops have often been used, except that herbicides or tillage are then needed to bring down the cover crop in the spring, both of which are detrimental to building good soil life and maintaining soil structure. Instead of using a tall grass or row crop species, use a short canopy (1/2 inch tall) plant species that goes dormant when water becomes limiting, or when it is shaded by the over-story plant. Direct drill or strip till the row crop plant into the system, and maintain the under-story cover year-round. This reduces erosion. The reduction in evaporation from the bare soil surface is more than enough to make up for water use by the cover crop in the summer. It is a bit of mythology that ground covers always take moisture away from the over-story plant. Studies showing ground covers take away water from the crop may have been biased by the funding source. Those studies need to be repeated by researchers with no connection to herbicide companies.

Figure 9. Melons in Australia. Shane Gishford, an SFI advisor in Brisbane, Australia, used compost in the soil and three applications of foliar tea applications in the growing season. Weeds, insect pests and fungal pathogens were significantly reduced, while yield was increased, water use was decreased, and rooting depth improved.

 

 

Figure 10. Radish grown in potting soils, with either a compost tea (Nature's Solutions product), or a common inorganic fertilizer addition. Plants with the compost tea clearly were far ahead of the inorganic fertilizer, and remained more productive through their whole growth cycle.

RADISH SEED T

Planted on Novsmb« 7, 2QQ4 on December 18. 2OO'!

 

NATURE'S SOLUTION & MIRACLE GRO RADISH TRIALS (H

Turf

Perennial grass systems are a bit different than annual systems and turf is unique in many ways. Turf will be walked on, whether by grazing animals, golfers, football or soccer players, or by people strolling on a lawn. Compaction is a never-ending issue with grass systems of any kind. The food web has to be healthy enough to maintain soil structure and not succumb to compaction.

Application of pesticides or high amounts (over 100 pounds/ac) of inorganic fertilizers will kill organisms in the soil, and disease will be the likely result. Instead of toxic chemicals, try the following:

1. Apply 1 to 2 ton per acre of finely sieved worm castings or worm compost in the fall (the sieved

compost should be able to shift between the blades of the grass to lie on the soil surface), or

2. Apply 15 to 20 gal/ac (150 - 200 L/HA) foliar compost tea application.

3. Apply 5 gal/ac compost tea (50L/HA) each week until frost occurs, and then hold off on any more

applications until spring.

4. Again in the spring, apply 1 to 2 tons finely sieved worm compost/castings to highly compacted

areas (the greens), and where needed in to fairways, tees and putting surfaces.

5. Apply 5 gal/ac compost tea through the summer until diseases are gone, or poorly covered or

thatch problem areas are grown in.

If aeration is needed, a practice that should rapidly end as turf health improves, apply a good compost tea (match the needs of the soil with the biology in the tea) immediately and then fill the aeration holes with a mix of 15 to 30% medium sieve compost high in woody or fungal foods, and 70% to 85% sand. Add VAM inoculum in the tea and compost material if the roots of the grasses are not mycorrhizal enough. Add humic acids if colonization is present but inadequate.

Figure 10. Rugby Club in southern England used the typical Soil Foodweb approach, with the

following results. For details contact Mike Harrington, Laverstoke Park, England.

FROM THIS TO THIS IN ONE YEAR

 

Orchards and Vineyards

In these perennial systems, an under-story cover crop is required in the tree, vine or berry bush row in order to prevent herbicide sprays in the area that needs to be fully fungal dominated. The under-story plants need to be fungal dominated, need to be good weed mats to prevent weeds from growing in the tree rows, should be colonized by the same kinds of mycorrhizal fungi as the over-story tree requires, should be short canopy so mice cannot girdle the trees without the predatory birds seeing them, and should easily go senescent or dormant in a dry summer period, but otherwise maintain a good layer on the surface so the soil does not dry out. During the summer, the grass in the inter-row areas should be mowed and blown onto the row area under the trees. This allows composting to continue all summer long. The under-story plant should be able to let grass clippings blown on top of the plants shift between the stems and reach the soil surface.

In the fall, compost should be applied at 5 to 10 tons per acre under the rows and again, the compost should be able to sift between the plant stems to reach the soil surface. Apply compost tea at 15 gal per ac after all leaf fall has occurred, in order to cover all leaf litter surface. This prevents diseases from being able to grow on the leaf material and overwinter. Leaf litter should be 50% reduced in weight within one month. If the leaf residues are not 50% gone within one month following leaf fall, apply tea again to speed the decomposition process. Leaf litter should reduce by well over 50% the amount of disease that occurs in a conventional orchard.

In the spring, if needed, apply another 1 to 5 tons of compost followed by a soil drench of compost tea. Then, 2 weeks before bud break, apply foliar compost tea to establish the beneficial organisms on all the leaf surfaces. For as long as no foliar disease is found, only apply tea in a foliar fashion once a month. Avoid applying foliar teas when pollination is at its peak. If a disease outbreak occurs, it may be necessary to apply the tea each day until the disease is out-competed.

Landscape Trees

In these systems, the challenge is to maintain the soil biology appropriate for the plant desired, even though a bacterial-dominated plant is within inches of a plant requiring fungal-dominance. This spatial heterogeneity is maintained by use of bacterial and fungal foods applied correctly to the root system and drip line of each plant. Management of the proper biology is maintained in this fashion.

Trees may need to have root trenches dug several feet deep, fungal-dominated compost added to the trench and then filled in with the soil, after applying a strongly fungal-dominated compost tea. While no guarantees can be made about effectiveness, in many cases effects of root rots, wilts, blights and other fungal diseases have been reversed by application of compost tea. The proper biology will compete with, and possibly prevent the disease from establishing on roots of trees. Work by a number of Soil Foodweb Advisors has shown that the use of tea has suppressed disease, and possibly prevented disease. However, a great deal more work is needed before we can say for certain that compost tea can consistently and with complete assurance work to remove disease from perennial root systems.

Greenhouse

Apply aerobic woody compost at about 30 to 50% in potting mix to replace peat moss and/or coconut fiber. Drench flats with compost tea to make certain the beneficial organisms are established. For vegetables to be planted in the field, place seeds rolled in compost tea and VAM spores in 100% good compost, or dilute the compost by half or three-quarters. Teas should be applied as soon as first true leaf stage is reached. All watering events should include some compost tea to maintain healthy root systems and maximize rooting depth. Drench the soil with compost tea just before sales.

Hydroponics should have 1 gal of compost tea added per each 50 gals of water. Beds or "soil-less" potting mixes should be drenched with compost tea to establish the beneficial organisms that will protect plants. Roots systems in aeroponics should be misted with compost tea instead of Hoaglund's solution. In water systems, again, 1 gal of compost tea should be added to 50 gal of water to prevent disease. In the case of water lettuce, for example, the entire plant should be dipped into compost tea made without humic acid (the humic acids can cause spotting of the leaf surfaces). Aquatic bulbs should be immersed in compost tea for 10 to 15 minutes before planting in order to establish the beneficial organisms around the bulb and on the roots. Compost tea should be added periodically to the water.

Nurseries

Potting soils should contain 30 to 50% aerobic compost, as a replacement for peat moss or coconut fiber. Beds should be made with 30% to 100% aerobic compost and drenched with 15 gal per acre (150L/HA) as-fungal-as-possible compost tea immediately before planting. Bare root plants should be dipped in compost tea with VAM spores (see spore package for density of spores) and then planted into the beds. Foliar surfaces should be treated with compost tea (5 gal per acre) each month or more often if disease requires. Soil drenches should be performed before planting and when litter or residue need to be decomposed. If possible, addition of compost tea to the watering system will reduce disease out-breaks.

Ponds and Lagoons

Aeration is the most important factor in maintaining pond or lagoon health. Plants can contribute to aeration, but if a layer of algae begins to grow, or if food resources (like manure) going into the pond or lagoon increase organism growth beyond the rate at which oxygen diffusion or photosynthesis adds oxygen to the pond, the pond will go anaerobic. Stink begins. Either reduce input of foods (manure, sugars, and dead plant material) or increase rate of aeration. Algal blooms may be adding oxygen into the water on the surface, but as the lower layers of algae die, and the dead bodies are decomposed, oxygen uptake increases, often beyond the level where the photosynthesizing algae can offset the oxygen demand.

At this point, aeration of the lower levels of the water in the pond must occur. Thus, any aerator needs to pull water from the bottom of the pond, not just stirring the surface waters. Addition of the beneficial organisms that were lost when the water went anaerobic is a must. Thus, compost tea needs to be added to the water, at 1 gallon per acre foot of water. Just an inoculum is needed; the foods are present, and aeration is occurring. Recovery can be rapid. As long as the pond or lagoon does not become anaerobic again, that single application of compost tea should be adequate to re-establish the needed biology.

The basic approach to using compost tea in conjunction with compost and soil should be apparent by this point. There are additional factors to be considered in making certain compost tea is disease-free and capable of giving the best benefit.

 

Factors Affecting Compost Tea Quality

Compost tea can be inconsistent from batch to batch, but this variability is actually relatively easy to control. When making tea, test the tea periodically to make sure the set of organisms in the tea is maintained and no unexpected problems occur to harm extraction and growth of the organisms.

Added Materials. Many ingredients can be added to compost tea to enhance the growth of specific microorganisms and provide micronutrients for plants. This manual gives a basis for choosing some of these materials (see The Recipes later in this manual), but a great deal more work is needed to understand why some additives work in certain conditions but not in others. It is important to recognize that only certain microorganisms will be encouraged, or selected by different foods. Combine food resource with aeration, pH, temperature and interactions with soluble compost material, and very different organisms can grow at different times. Make certain that the kind of compost, the temperature, etc are maintained the same, and each tea brew can be very similar.

Aeration. Oxygen is required by all aerobic organisms. A large problem in making highly beneficial teas is when microbial growth rapidly uses up a significant portion of the oxygen such that anaerobic conditions ensue, and materials that are toxic to plant growth are produced in the tea. Properly controlling oxygen input into the water is critical. It is a wise idea to buy an oxygen probe in order to make certain the tea remains in the aerobic range (above 6 ppm or 70 to 80% dissolved oxygen - versus carbon dioxide - in solution, or 20 to 22% oxygen as total atmospheric gases; see Table 3 below).

Table 3. Relationship between Oxygen, Carbon Dioxide, and Aerobic, Facultative Anaerobic and Anaerobic Organisms

Type of Organism Total Atmospheric Gases Percent Dissolved Gases Dissolved Gases (mg/L)

Aerobic 20 -21% oxygen 1 to 6% carbon dioxide 95 to 98% oxygen 1 to 5% carbon dioxide > 6 mg/L oxygen

Facultative Anaerobe 15-1 6% oxygen 6 to 12% carbon dioxide 75 to 95% oxygen 5% to 25% carbon dioxide 4 to 6 mg/L oxygen

Anaerobe 2 to 15% oxygen > 12% carbon dioxide < 75% oxygen > 25% carbon dioxide < 4 mg/L oxygen

Temperature and air pressure (elevation) Percent oxygen declines and other gases increase as elevation increases Oxygen and carbon dioxide will always sum to 100% regardless of elevation, pressure or temperature Maximum concentration of

oxygen at sea level, freezing is 16 mg/L, decreases as temperature increases or air pressure decreases

 

 

Oxygen has to diffuse into water at the interface between air and water. By bubbling air into water that interface is increased, resulting in more diffusion of oxygen into water. The smaller the bubble size, then the greater the exchange surface and the more efficient the transfer of oxygen into the water. Bubblers that decrease the size of individual bubbles improve the oxygen content of water more rapidly than aerators with larger size openings to produce bubbles. Of course, if the bubble size is extremely small, then airflow may be restricted because it is harder to push air through a small opening. Aquarium bubblers typically produce rather large size bubbles and are not very efficient oxygenators of water, but they are very inexpensive and can run all the time. Depth of the water is important too, since in order to produce a bubble, the air pressure must be greater than water pressure, and water pressure increases with increasing depth. Thus an air pump adequate for a 5-gallon machine may not be adequate for a 500-gallon machine, depending on the water depth.

If bacteria and fungi are not growing, tea solutions will remain well oxygenated. Bacteria consume the majority of the oxygen during aerobic metabolism. If the oxygen is replenished at a rate greater than what is consumed by the bacteria, the tea will remain aerobic. Conversely, when oxygen is consumed at a rate greater than the rate at which it is replenished, the tea will become anaerobic.

When dealing with tea, and the need for a short brew cycle, the growth of bacteria and fungi can be so rapid that air can be drawn below aerobic levels extremely rapidly, within an hour or less of adding molasses, humic acids or other food resources. Therefore, air needs to be provided at a relatively high rate to offset the use of oxygen by the aerobic, beneficial organisms.

Teas can become anaerobic if molasses or sugar is added to the solution. The offensive odor produced (rotten egg smell, vinegar or sour smell, sour milk or vomit smells) is an indication of anaerobic conditions. However, if the tea is allowed to continue "fermenting," microorganism growth slows as food resources are used up. Oxygen will begin to diffuse into the tea more rapidly than it is consumed by bacterial and fungal growth, and aerobic organisms will begin to grow using the organic acids produced during anaerobic metabolism. The tea will become aerobic again.

Strict aerobes require oxygen concentrations around normal atmospheric levels (18 to 22% total atmospheric gases or 8 ppm, or 8 ug per liter; see Table 3) in order to perform the functions of life. Examples of some of these genera of bacteria are Pseudomonas, Bacillus, and Aerobactor. As oxygen concentration is reduced, dropping below 5 ppm, strictly aerobic organisms will become dormant, and eventually die. Lack of oxygen allows the growth of facultative anaerobes (which switch from aerobic to anaerobic metabolism when oxygen levels fall below 15 to 16% O2 or 5 to 6 ppm oxygen). Examples of

bacteria that are facultative anaerobes are E. Coli. Klebsiella. And Acinetobactor). True anaerobic bacteria cannot tolerate O, above 7 to 8%, or 4 to 5 ppm oxygen while strict anaerobes require low oxygen

concentrations (less than 2% oxygen) to grow.

Anaerobic organisms are not detrimental in themselves, but their metabolic products can be extremely detrimental to plants as well as many beneficial microorganisms. Anaerobic metabolites produced are volatile organic acids (valeric acid, butyric acid, phenols, see Brinton, 1997) that are very detrimental to the growth of plants and beneficial bacteria, fungi, protozoa and nematodes. Anaerobic products may kill some disease-causing microorganisms, but usually the death of a few disease-causing microorganisms is not positive enough to offset the reduction in plant growth.

When aeration is too great, the tea can become over-charged with oxygen, which can be detrimental to beneficial microorganisms. However, there is no compost tea maker on the market that over-charges tea. Only if someone decided to add hydrogen peroxide, or ozone to the water would it be likely that the water could have too great an amount of oxygen.

Aerobes, facultative anaerobes and strict anaerobes are everywhere. They live in soil, on plant surfaces, on the surfaces of stones, on and in pavement and clothing. Facultative anaerobes include some species that are highly beneficial to plants as well as some disease-causing species. These microorganisms are needed so that the cycling processes within nature can occur. Thus, sterilization of tea is not the answer. Many highly beneficial microorganisms would be lost if the tea were sterile. The goal is to keep the tea fully oxygenated and maintain aerobic conditions, so that the benefits from a widely diverse set of microorganisms can be realized.

Organism growth in a batch of compost tea follows a typical pattern (Fig. 11). The organisms first adjust to the liquid environment as the organisms and the soluble nutrients are ripped off the compost by mixing and aeration. Adjustment to changes in temperature occur as well, although it may take a few hours for that adjustment to occur, called lag time, before growth commences again. The temperature of the water should match the temperature of the soil, or leaf surfaces, depending on the purpose of the tea application.

As the organisms grew faster and activity increased rapidly, both foods and oxygen were depleted. At a certain point, which is dependent on the food resources added, the aeration rate and the rate of movement of water through the compost and tea brewer, the organisms used up oxygen at a rate faster than the machine was adding air into the water. As a result, oxygen levels in the water dropped. The point at which organism activity peaked (green triangle line), the organisms had used up the simple, easy-to-use foods in the tea and growth begins to wane.

At that point, the organisms are no longer using up oxygen faster than it can be replaced, and oxygen concentration in the water begins to increase. As the organisms stabilize, their activity reaches an equilibrium for the next few days.

The critical part of the curve is the relationship between organism growth causing oxygen to dip into anaerobic ranges, and aeration rate. In these teas (Fig 11), filamentous fungi, protozoa and beneficial nematodes were lost as oxygen was depleted and fell below 6 micrograms oxygen per ml (or 6 mg oxygen per L). These teas could not suppress foliar disease on the plants they were applied to, because the beneficial fungal were lost.

Compost Tea Oxygen Levels

 

 

0 3 7 11 15 19 23 27 31 35 39 43

 

Figure II. This curve was generated based on eight tea brews using the same recipe with I gal molasses and I gal dry kelp product. Note the lag time associated with addition to cold water which must be overcome by the organisms early in the tea brew.

Brewing time. Up to the point that most of the soluble nutrients are all extracted from the compost, and most of the organisms capable of being pulled from the compost are off the compost, the longer the time the compost remains suspended in the water or tea solution, the greater the amount of soluble material extracted from the compost and the greater the number of organisms extracted. More soluble material in the tea means more food resources to grow beneficial bacteria and fungi, and more nutrients that will potentially be made available for plants.

The easiest way to know how long a machine takes to make tea with adequate organism numbers in it is to measure them over time.

Organisms growing in tea consume the extracted nutrients, immobilize them in their biomass and keep the nutrients from washing through soil or off the leaf surfaces. If the tea is well mixed and well aerated (see Compost Tea Production Methods), all these processes will be maximized.

If oxygen supply is not adequate, bacteria and fungi growing in the tea can use oxygen faster than oxygen diffuses into the tea, and then anaerobic organisms grow in the tea with the production of potentially phytotoxic materials in the tea. Any corner of less than 120 degrees angle tends to be a place where bio-films form rapidly, a well-known phenomenon in the world of biofouling. Despite any amount of mixing in the container, the "dead-air" effect of a corner results in no replenishment of well-oxygenated water, so that oxygen is rapidly depleted as microbes grow. Thus corners can result in the production of rank-smelling materials, and have quite negative impacts on plant growth if these anaerobic decomposition products are not used by aerobic organism growth before the tea is placed on or around the plant.

The shorter the brew time, the less likely it is that anaerobic bio-films can develop. Thus there is a balance between extraction of nutrients and growth of organisms, giving an optimal time for tea production, depending on the exact conditions of brewing.

The longer the brewing time, the more likely weather will change and application will have to be put off. With longer brewing times, the organisms in the tea will use up all their food and go to sleep, or if brewing times are very long, some of the organisms colonize the surfaces of the containers and begin to develop anaerobic layers on the container walls. Thus, there needs to be a balance between the time organisms immobilize nutrients extracted from the compost and the time they will begin to colonize the container walls and produce anaerobic layers.

Each tea brewer has an optimal time for extraction unique to the design of the machine. For example, the Microb-Brewer and the Earth Tea Brewer can produce the optimal number of organisms within 20 to 24 hours when run at room temperatures (colder temperatures require longer brew times). The bucket method of brewing (see Ingham, 2000) requires 3 days, and some trough methods of production, and most not-aerated brews require 2 to 3 weeks.

Not-aerated, no-nutrients added tea brews may have such low numbers of organisms in a tea that bio-films never develop and the liquid never becomes anaerobic, no matter if the liquid is never stirred or mixed or aerated. If the tea does not contain many organisms, the tea cannot have the benefits that organisms give that have been discussed previously.

Compost Source and Quality. All of the soluble compounds in compost can be extracted into the tea. It is essential, therefore, that only beneficial food sources be present in the material being extracted. Only by composting correctly can this be assured. Whether using thermal, or static compost, temperature must have reached AT LEAST 131 to 135° F (57° C) continuously for 3 entire days throughout the entire pile (the surface of the pile is not at 135° F (57° C), so the outside material must be turned to inside and temperature maintained). The material cannot have been anaerobic for any length of time or phytotoxic compounds may be present, and nutrients will volatilize if the compost becomes anaerobic. If worm-compost (vermicompost) is used, the material does not have to reach temperature, but must be adequately processed by the worms. Passage through the earthworm digestive system kills human pathogens and most plant pathogens, although more work needs to be performed to document this in a fully scientific manner. Adequate time in the worm bin must be allowed for full processing of all materials by the worms to occur.

All of the species of organisms that can be detected in the compost will be extracted into the tea. This does not mean all individuals of all species will be extracted however. Many individuals will be left in the compost, so the compost can be re-added to the compost pile. If pathogenic or pest microorganisms are present in the compost, then they too will be extracted into the tea. Therefore, GOOD COMPOST, which does not contain significant numbers of active disease-organisms, is essential.

If compost is properly made, disease-causing microorganisms will be killed, out-competed, inhibited or consumed by beneficial organisms in the compost, or in the tea. A huge range of beneficial food resources is made during the composting process (see Cornell's Handbook on On-Farm Composting, Rodale's books on composting, and the Soil Foodweb Web Site for more information on making good compost).

How do you know compost you buy is good? Data are REQUIRED. Ask your compost supplier to show the temperature information on the batch you are buying. Ask them to show you the data on oxygen concentration (or the reverse measurement, carbon dioxide concentration) during composting. Because the heat during composting is generated by bacterial and fungal growth, that increase in temperature also reveals whether bacteria and fungi used up oxygen and if the compost became anaerobic during peak temperature times.

Temperature should, however, not exceed 155° to 160° F (68° to 71° C) and the oxygen level should not drop below 12 to 15%. When temperature reaches these high ranges, oxygen is being consumed rapidly, and anaerobic conditions, with production of phytotoxic materials, is quite likely. If compost gets too hot, does not heat enough, or becomes anaerobic, the set of organisms in the compost is not desirable. If you use poor compost, the tea will not contain the desired set of organisms.

A good test of compost that you can do yourself is determining smell. It should smell like soil, or mushrooms that you buy in the store. If compost went anaerobic for a significant period of time, it will smell sour, like vinegar, or sour milk, or vomit, rotten eggs (hydrogen sulfide) or urine (ammonia). Not only will the material have lost nitrogen and sulfur (and why would you pay good money for something lacking fertility?), but it also contains phytotoxic materials that can kill your plant if they encounter any plant surface.

In order to maximize populations of beneficial organisms, it is important that an adequate range of food resources be extracted from compost into the tea. This can only occur if organism numbers are adequate in the compost. It is the organisms that make humic and fulvic acids. Minerals will be extracted from the compost as well, making it critical that the salt level not be too high, and that no toxic chemicals, or at least no high concentrations of toxins, be present.

Extraction and Mixing. Mixing needs to be not too much and not too little. Too rapid mixing will physically destroy beneficial microorganisms in the tea. Think about yourself impacting the wall of the container going 320 km (200 miles) an hour. If the speed of the impact would kill you, it will kill the organisms in the tea. Too slow mixing means a lack of organisms pulled from the compost, allows bio-film development to be rapid, and the surface of everything will develop an anaerobic slime with resulting phytotoxic materials present in the liquid.

There are two things to understand about mixing.

1. Enough energy has to be imparted to the compost to physically remove the bacteria and fungi

from the surface of the compost. Bacteria can glue themselves onto the surface of any particle

in compost, and it takes significant energy to remove bacteria from these surfaces. Fungi wrap

around particles and the hyphae have to be broken enough to let the strands be pulled out of the

compost, but not broken so much that they are shredded into tiny pieces. Thus, most extraction

methods that involve blades, whirring mixing bars, or blender action can break up the hyphae,

or the bacterial cells, too much and result in poor fungal and/or bacterial biomass in the tea.

2. Uniformity of the end product, the tea, is necessary. Good mixing - enough but not too much -

produces both effects. Most of the commercially available machines were developed around the

principles of enough aeration and enough mixing to get organisms into the tea, but not shred

them to death.

If brown color comes from the compost, then fungal extraction is probably good. Add fungal food resources and surfaces that will allow fungi to grow in liquids. So, BEFORE placing any dark-colored materials in to the tea water at the beginning of the cycle, add the compost into the tea maker, in whatever container you have, and make certain the compost tea-maker is mixing the water well enough to pull the humic acids (brown color) from the compost. No brown color out of the compost in the holder should instantly indicate that adequate extraction is not occurring. Additional mixing of the compost in the container will be necessary.

Foam. The presence of foam on the surface of tea is considered a positive sign, but just means there are free proteins, amino acids or carbohydrates present. This can occur as the result of adding fish hydrolysate, certain organic acids or carbohydrates. If worm compost was used, excessive foam suggests a few earthworms were in the compost and their dead bodies are providing this source of protein/carbohydrate. Excess protein or amino acids should not occur if bacteria are growing well, although dead worms may continue to release proteinaceous materials throughout the brewing cycle. Foam can be suppressed by using organic surfactants, such as yucca or vegetable oil (not olive or canola oil!). Don't use commercial de-foamers - every single one we have tested kills the organisms in the tea.

Maintaining Compost Activity. If a large amount of compost is bought to make tea during the rest of the year, be aware that the organisms in the compost go to sleep, become dormant, and don't extract from the compost easily the older compost gets. Maintain compost organism activity by adding compost tea to the compost. Even then, we have seen a compost get so "mature" that you can't wake them up to grow at all in a 24 hour brewing cycle.

Compost for foliar compost tea applications should to be SLIGHTLY IMMATURE! That means, a little bit of temperature is a good thing - about 5° - 10° above ambient is the desired range.

Mesh size of the tea bag or final filtration material. The opening size in the compost container or any filters through which the tea must pass, can affect the kind of particulate material and organisms that will be present in the tea. Mesh is a measurement of the number of holes in an inch surface area, the smaller the mesh number, the larger the size of the holes. For example, an 80-mesh screen has holes with diameters of 170 micrometers (a micrometer is a millionth of a meter). A 20-mesh screen has holes with diameters of 800 micrometers.

The finer the size of the openings, the more likely only soluble components will be extracted. If the openings are too large, particulate matter in the tea may clog sprayers and irrigation systems.

A variety of materials can be used, as long as they are inert to microbial decomposition. For example, polycarbonates, plastic, nylon, silk and fine-weave cotton work well, but window screening, wire mesh, and burlap may also be used. Fresh burlap should be used with caution, though, as it is soaked in preservative materials which can be extracted into the tea and kill the organisms.

Consider the size of the organisms desired in the tea. The largest beneficial nematodes are around 150 to 200 micrometers (10~6 meters) in length, but only 30 to 50 micrometers in diameter. Thus, a mesh that allows organisms of this size to pass, but restricts passage of larger materials, is desirable. The openings should not be smaller than this size since then a number of the beneficial organisms would not be present in the final product.

Microbes in tea. A wide diversity of bacteria, fungi, protozoa and nematodes need to be present in the compost and be extracted into the tea (see previous discussion of the organisms in tea). The greater the diversity of beneficial microorganisms, the greater the likelihood that disease-causing organisms will be out-competed on leaves, stems, roots or in the soil.

Nutrient retention will be higher, because all the food resources will be used and the nutrients retained and not leached from the leaf, stem, root or soil. Plant-available nutrients will be cycled at a more beneficial-to-the-plant rate, and soil aggregation will improve, along with water-holding capacity, breakdown of toxic materials and decomposition rates.

When the diversity of microorganisms in the compost is low, the health of plant surfaces will be limited, and one particular set of metabolic products can accumulate to the detriment of plants and other microorganisms. Thus good compost is critical to the production of good tea (see Wagner, 2000, Rodale books on composting, the Soil Foodweb website, www.soilfoodweb.com for information about the set of organisms in good compost and how to tell if they are present).

Ratio of Compost to Water. The dilution of soluble materials and microorganisms extracted into the tea is important. Too little compost will result in too dilute a tea with too few nutrients or organisms. Too much compost means not everything is extracted that could be extracted. If the "spent" compost is placed back into an active compost pile, then "wastage" isn't a worry. But it may be possible to overload some tea makers with too much compost, such that water cannot flow through the compost and extraction efficiency will be low. Because the optimal ratio of compost to water tends to be variable, experiment with the amount of compost put in your compost tea brewing machine to find the best ratio. If your machine calls for 7 pounds or kilos of compost, try 6 or maybe 8 pounds or kilos and see if the amount makes a difference.

Temperature. Temperature, humidity, evaporation and other abiotic conditions influence the growth rate of microorganisms. For example, high temperatures volatilize nutrients. Evaporation concentrates salts, while low temperatures slow microorganism growth. Obviously, these conditions can have a significant influence on the quality of the tea. Again, experiment a bit to find the optimal temperatures for your particular situation.

Place the tea making equipment inside a greenhouse or shed. In hot weather, cover or shade tea-making units prevent evaporation and concentration of salt.

In machines where the tea goes through a pump, the growth of microorganisms elevates the water temperature, but as long as the tea is well mixed, temperatures will not exceed 100° - 110° F (38° - 43° C). If temperature in the machine exceeds 100° F (38° C), something is wrong with the pump, or too much biofilm has developed in the pipes or tubes, suggesting that the machine should be cleaned to remove restriction of the passageways in the machine.

Machines mixed using aeration, where the tea does not go through the pump, are cooled by the temperature of the ambient air and rarely have an increased temperature. In these machines, it is wise to use a tank heater to raise temperature and increase microbial reproduction.

Water Source. Water high in salts, heavy metals, nitrate, chlorine, sulfur, tannic acid, carbonates, or contaminated with pathogens (human, animal or plant disease-causing microorganisms) should not be used. Where present, removal of contaminants becomes a priority before using the water. Both chlorine and sulfur can be removed by aeration. Carbonates can be removed by precipitating them with additives, and then de-gassing those additives. Contact your water treatment department or send a water sample to a testing lab for analysis. Or, try some of these simple assessments: Drink a glass of bottled water (make sure it is less than 1 ppm (u.g/ml) nitrate. Drink a glass of your own water.

• Bitter? May be high in nitrate.

• Rotten egg taste or smell? High sulfur.

• Chlorine smell? High chlorine. Keep aerating, or remove chlorine with reverse osmosis or a

chlorine filter.

• Slippery feel to the water? High in carbonates. Use some acid to remove the carbonate and

balance the pH

• Earthy taste? Algae or actinomycetes (actinobacteria) present. Find a better source of water.

Compost Tea Standards

The desired MINIMAL ranges for active as well as total bacteria, active and total fungi, protozoa and nematodes in a good tea, i.e., one that will begin to move the soil in the direction of improving the communities of beneficial organisms and provide the benefits discussed previously (page 7). In order to see these benefits, the following points must occur;

1. Adequate amounts of tea, with adequate concentrations of organisms must be applied to the plant

surfaces.

2. Cover plant surfaces at least 70%,

3. At least 5 gallons of tea should be applied per acre (50L/HA) for leaf coverage, and 15 gallons per acre

(150 L/HA) for a soil drench,

4. The organisms have to survive the application,

5. The organisms require foods to begin to grow,

6. If disease is already present, it may be necessary to displace the disease through the mechanisms of

competition for space, food, or infection sites. There is little evidence that antibiotic or toxic-

compound production is a major, or even important, mechanism. Therefore use of the term "bio-

pesticide" or "pesticide" is NOT appropriate for the mechanisms by which compost or compost tea has

it's major, or most important, impacts on disease.

The following table lists the minimum levels of each organism group required in compost (per gram dry weight of compost), or in the tea (per mL of tea before spraying).

Table 4. The desired minimal ranges for different organisms in compost or compost tea.

(#)

Compost

(per gram dry weight) Active Bacteria(ug)=15-30 Total Bacteria (ug)=150-300 Active Fungi(ug)=2- 10 Total Fungi (US)150 -200

Protozoa (#) F=10,000, A=10,000, C=20 to 50 Beneficial Nematodes=50-100

Compost

tea (per ml) Active Bacteria(ug)=10-150 Total Bacteria (ug)=150 -300Active Fungi(ug)=2- 10 Total Fungi (US)=2-20 Protozoa (#) F=1,000 A=1,000, C=20 to 50 Beneficial Nematodes=2-10

fjg means microgram, or one millionth of a gram. A gram is about one teaspoon

Active Bacteria - The biomass of bacteria performing measurable aerobic metabolism Total Bacteria - All of the bacterial biomass present, including the sleeping, dormant, inactive and not-very-active portions of the community. Gives a relative idea of whether adequate bacterial diversity is present.

Active Fungi - The biomass of fungi performing their functions right now.

Total Fungi - All of the fungal biomass present, including active, inactive and dormant. Gives an idea of the diversity Must be adequate in order to be able to prevent diseases under all conditions. Protozoa - All three groups cycle nutrients from bacteria into plant available forms. Flagellates and amoebae are strict aerobes. Ciliates prefer to feed on anaerobic bacteria and thus indicate that the conditions are conducive to anaerobic bacteria growing. Higher than the desired range of ciliate numbers indicates lack of oxygen somewhere in the material. If flagellates and amoebae numbers are above the desired range, then even greater than minimal nutrient cycling will occur.

Beneficial nematodes - These are the bacterial-feeding, fungal-feeding and predatory nematodes. They consume their prey group, and release nutrients from the prey group into plant available forms. The greater the diversity of these groups, the more likely nutrient cycling will occur in all conditions.

There will be variability from tea-to-tea, even if compost, mixing, amendments used, etc. Are the same. But that variability is not excessive, and typically is no more than 10% for bacterial and fungi biomass, and up to 20% for protozoa. Note that for ciliates, numbers should not exceed greater than 100 individuals per ml of tea, as this would indicate limited oxygen conditions (anaerobic) in the tea. Tea can be diluted if the biomass of all categories will still be within desired ranges AFTER dilution is complete. If the biomass/numbers are lower than the desired range, the amount of tea sprayed will have to be increased from the 5 gallons per acre typical to achieve the desired coverage.

In all the studies performed the organisms must occupy AT LEAST 70% of any plant surface. The desired ranges are 60 to 70% for bacterial coverage, and 2 to 5% fungal coverage, for a total of at least 70% coverage.

Comparison of a Not-Suppressive Tea with a Suppressive Tea

How do you know compost tea is doing the job? Well, which job are you interested in? If it is protection of a plant from disease, then to document protection, you need to have plants that you know are being attacked by the disease, and you need to show that the plant does not come down with the disease.

Do this experiment yourself, and demonstrate whether your tea is doing the job. Protocol:

1. Plants were from a nursery where the greenhouse was infested with blight. All plants were infested,

and the greenhouse was being fumigated to get rid of the problem. Plants from the greenhouse were

donated to SFI. Presumably all plants remaining at the nursery succumbed to the disease.

2. Two compost teas were made. The suppressive tea was made in an EPM 100 gallon tea maker. The

not-suppressive tea was made in a home-modified version of a commercially available tea machine.

The EPM machine used 10 pounds of compost (mixed 50-50 thermal and worm compost), while the

modified machine used 5 pounds of compost in a fabric bag. The recipe used was the same in both

machines: molasses and kelp, aerated water, at ambient temperature (about 65 F air temperature at the

start; water temperatures slightly lower).

3. The teas were brewed for 24 hours, and applied to the tomato plants using a hand-held spritzer.

4. All leaves were well-covered with the straight tea.

5. Tea samples were removed for SFI methods and for plate count analysis (dilution series was begun).

The process of clean-up took about an hour.

6. Leaf samples were removed from the plants (leaves were dry), stained and examined using SFI

methods.

7. Tea was assessed using SFI methods (1:10 and 1:100 dilutions used), and plates were spread for plate

count assessment (1:10, 1:100, 1:1000, 1:10,000 and 1:1,000,000 dilutions spread plated as needed).

Results: The following table shows the results from this study. It is clear which tea was able to protect the plant and which tea was not able to protect the plant, based on the fact that all plants died in the non-suppressive tea trial, and all the plants lived in the suppressive tea trial. There were five plants in each treatment, and several hundred plants in the control (the plants in the greenhouse succumbing to disease when the tomato plants were given to SFI for this trial).

The plate count data are shown as they would be reported from a standard plate count lab. These are the Colony Forming Units, or Most Probable Number of individual bacterial cells that can grow on these specific media, under the specific incubation conditions in the lab. The problem with Pseudomonas counts is that you cannot tell whether these are disease-causing Pseudomonas species, or beneficial species. The not-suppressive tea had higher counts of bacteria that can grow on King's B medium, but does that mean more or less suppressive species? You cannot tell from this assay.

The Cellulase-producing bacteria and fungi were higher in the suppressive tea, but not by a significant amount. In the BBC "Species Richness Diversity" Index, this difference in CPU would not result in a different index reading. So, is it significant? There is no way to tell.

The number of spore-forming bacteria and fungi were higher in the not-suppressive tea, but again, were these beneficial species, or were these the disease-causing species? Just because a number is higher, and would perhaps get a higher "index value" from a BBC Lab assessment does not mean anything beneficial. A higher number of disease organisms is not a beneficial thing.

The comparison of aerobic to "anaerobic" bacteria was not performed, because this is a truly meaningless test. Many, if not most, of the bacteria that grow on the aerobic plate are in fact facultative anaerobes. That means, they will grow on the "anaerobic" plate was well as the aerobic. So, what does it mean that some grow on both plates? Which are the strictly aerobic species, and which are the disease-causing switchers? The "aerobic/anaerobic ratio" calculated from these plate methods cannot give that information. It is a meaningless ratio unless there are data showing that plants die when the ratio is at some level, and what plants are benefited at some other ratio. Once that information is made available, then perhaps that ratio could be useful. The aerobic/anaerobic ratio has no data to back up what it means.

Table 5. How to tell that tea will be suppressive. Comparison of results from plate assessments and direct assessments when tea was not able to suppress disease, compared to when tea was able to suppress disease.

Tea Lacking Suppressiveness Tea Capable of Suppressing Disease

Plate Methods (MPN or CPU per ml)

TSA (Aerobic Bacteria) 1.6(0.5)X108 1.6(0.7)X 108

King's B (Pseudomonads) 5.0(1.4)X103 1.2(0.2)X103

Cellulose (Cellulase producers) 35(12) 210(43)

Spore-Formers (Bacillus sp) 7.9 (0.4) X 102 0.3(0.1)X102

Direct Microscopy (ug biomass per ml of tea)

Active Bacteria 8.0 (2.6) 12.7 (5.0)

Total Bacteria 25.1 (1.0) 245 (34)

Active Fungi 0.00 (None detected) 3.76(1.00)

Total Fungi 0.35(0.12) 11.1 (2.33)

Leaf Coverage (%)

Bacterial Coverage 27 (4.7) 86.9 (9.7)

Fungal Coverage None detected 5.1(0.6)

Disease (5 tomato plants) All plants died within a few days All plants lived and produced tomatoes

Numbers in parentheses are Standard Deviations of three readings taken for all the lab methods. These values indicate variation levels in the measurements taken.

It is clear from the direct microscopic methods which tea will be able to perform the job. Adequate fungi must be present to deal with blight. Without adequate fungi and bacteria covering the leaf surface, there will be no disease suppression. Both the assessment of the tea itself, and the leaf surface once the tea was sprayed out were predictive of whether the tea was going to be able to deal with the disease beginning to grow on the leaf surfaces. It is easiest at this time to use the direct assessment of the tea solution. Once we have the equipment to assess the leaf surface IN THE FIELD, this will become the more useful measure, most likely.

Will all fungi adequately suppress disease? There is probably some specificity of fungal species which are better at occupying the spaces on leaf surfaces, or using up the foods that the disease fungi need. Do we know if those fungi were present in this tea? No, we don't. That we had adequate fungi and bacteria present are clear. But, in the next tea made, will adequate species diversity, the right species of suppressive organisms be present? Most likely they will. But until we have methods that can measure that information, we are left to try to maximize the beneficial species in compost, and in tea, and let the plant do some of the work by putting out the foods that will feed the right fungi and bacteria to take care of the problems on the leaf surfaces.

Brewing Methods and Machines

Each kind of compost tea machine extracts, aerates and mixes tea differently than other machines. Yet, when the machines do a good job, the results can be quite similar. As long as the factors involved in making good tea are paid attention to, extraction, survival and growth of the organisms will be maximized.

Evaluation Criteria

Therefore, each machine needs to be evaluated based on the following factors:

1. Aerobic? Ability to maintain aerobic conditions (above 6 mg oxygen per L). This level is based on

effects on plants and leaf material. Burning, browning, lack of foliar pathogen control, lack of nutrient

color improvement all indicate anaerobic toxins produced. Quite often this is also related to

compaction of the compost in the container, and too many nutrients added as amendments.

2. Extraction of organisms from the compost? Did the machine extract the ALL the different kinds of

organisms? Some machines do not extract the fungi, protozoa and nematodes. Only by obtaining data

about these other organisms can their presence be determined.

3. Extraction of soluble nutrients from the compost? Did the machine extract soluble nutrients from

the compost? Or are the nutrients only from added materials? Then why make compost tea?

4. Compost compaction? If mixing and aeration are not adequate, the compost will compact, most

likely go anaerobic if there are organisms growing in the tea. The tea will lose the beneficial fungi,

because these beneficials require aerobic conditions in order to survive. Teas can go anaerobic

because oxygen is used up by bacteria and fungi growing in the tea and in the compost. Especially if

the compost does not have aerated water moving through it, the compost will go anaerobic and

anaerobic products from anaerobic bacterial growth will disperse into the tea, killing beneficial aerobic

organisms.

5. Amendments? Were adequate amounts of food added to grow beneficial organisms? Or too much

food, causing the bacteria and fungi to grow rapidly, and outstrip the capacity of the aerating unit to

keep up with their oxygen demand? Or food supply too low, resulting in extracted organisms, but no

growing organisms? The machine manufacturer should test their machine, and tell their clients the

correct nutrient concentrations to balance the growth of the organisms with the aeration rate. Please be

aware that higher temperatures mean less nutrient amendments can be added because the organism

grow faster. In addition, water that that is higher in temperature can hold less oxygen. As elevation

increases, less oxygen is present in the atmosphere, and so less rapid growth can be allowed before the

water goes anaerobic. Please see the USGS website for a table of these values.

6. Ease of Cleaning? Cleaning is serious business. In all production systems, a biological firm of

microorganisms, called a biofilm and sometimes much thicker than a film (up to an inch or more in

thickness in some systems), develops on surfaces. With time, the deepest layer of the film becomes

anaerobic, resulting in production of strong organic acids that can kill organisms in the tea, kill plant

tissue if applied to them, and can etch the tea-maker's surfaces. If the surface is metal, the metal will

be solubilized and end up in the tea solution. For this reason, a metal container is not recommended. If

brew time is short, and the unit is cleaned to remove the biofilm between brews, there will be little

problem. Wood or plastic containers are preferable because they can be easily cleaned.

Cleaning the tea maker is SERIOUS. If biofilms aren't cleaned off, tea may contain pathogens and other toxic materials that can harm plants. A bio-film doesn't necessarily mean things are terrible, but they always occur when a problem has been seen.

Early Methods of Compost Tea Production.

Bucket Method. Bucket methods date back to early Roman, Greek and Egyptian times (Brehaut, 1933, Cato's De Agricultura, Varro's Rerum Rusticarum Libri Tres). Many versions of "compost in a bucket" are still used today. Typically, the compost is either free in the water (which means that the non-soluble chunks have to be strained out of the tea if you want to put it through a delivery system) or suspended in a sack or bag, along with other non-soluble ingredients.

[Nesta 8]

Compost Tea 2010 - Bob Webster (1 of 8)

Nice Day

Nesta

[Tippie 0]

@ polletje, heb je dat echt allemaal gelezen

volgens mij is dat de langste quote ooit

[Boefje030 996]

Polletje, beetje beknopt beschreven allemaal he..

 

Heb je nog de fulltext hiervan ?

[pietjepuck 1]

kijk ook eens op youtube daar is ook genoeg te vinden over composttea.

[Nighthaunter 1]

Compost thee heb ik nog niet gemaakt.

Wel die mayan microzyme met honey en sannys bacto genomen zit ook gist in en humuszuren enz die 3 werken goed samen iig.

maar das voor de groei.

mischien met een sok er wat wormen mest ingooien voor de n ?

[Doc 12]

De Volgende producten zijn in verschillende combinaties bruikbaar.

Ik noem alleen de producten waar iedereen makkelijk aan kan komen.

 

zuivere wormenmest (geen wormenhumus)

zuiver compost (geen afvalcompost)

Batguano

Humboldt Honey

Sannie's Bacto

Mayan Microzyme

GL Batboost

[Nighthaunter 1]

In het verhaal lees ik ook over enzymen.

Mischien humboldt prozyme toevoegen ?

Ik gebruik dat ook elke week.

Humuszuur zit ook in sannies bacto maar ook in humboldt flavor full en humboldt humic

Ik las laatst ook iets of silicon wat vloeibaar is gemaakt ook door humboldt I.S. heet het dacht ik maar alleen in amerika te krijgen nog.

Het zou mooi zijn als iemand uitvind wat je precies moet hebben voor:

groeithee

bloeithee en de laatste weken bv meer posphor en kalium met guano en palmboom as thee

 

koop een goede microscoop om te kijken wat erinzit van bepaalde dingen

bacterieen schimmels en andere microben.

Ik zou zeggen nog genoeg te doen voor jouw polletje

[Doc 12]

Veel producten van Humboldt Nutrients zijn inzetbaar bij een thee.

De Mayan Microzyme is er speciaal voor gemaakt.

Ook de Bacto is een prachtig product.

Met thee kan je verschillende producten brouwen afhankelijk van de gebruikte ingrediënten.

Je kan een stimulator brouwen maar ook groei en bloeivoeding.

Voor een groeivoeding kan je testen met de GL bio-granulaat. npk 10-0-4 heb je ook meteen de suikers.

Sommige amerikanen doen er jaren over om hun eigen brouwsel te perfectioneren.

[polletje 21]

1e thee is in de maak met:

 

honey

mayan

bacto

wormenmest

en t spul wat er bij zit

drupje final solution

 

werkt leuk er is alleen 1 maar....

 

waarom maakt dat kutding net zoveel herry al 10 oude wasmachines op centrifuge stand!!!!

[Doc 12]

oeps dat was ik vergeten te melden

 

edit: als je hele goede thee maakt wil hij wel eens gaan schuimen.

Leg er voor de veiligheid een zeiltje onder of een wasmachinebak.

Of zet hem lekker buiten neer.

Dat moet geen probleem zijn in die vrijstaande boerderij van je.

[polletje 21]

ik maak er wel een box omheen....

[hupla 3]

pffw wat een lap text

ik kijk wel mee

en if polli wanna cracker with the tea,,just yell

[whazzup 165]

1. Either the food resources sold by the tea machine maker, or a standard set of foods, such as 0.01% fish

hydrolysates and 0.01% humic acid (1 gal offish, and 1 gal of humic acid in 100 gal of water),

 

ehm.. factortje 100 verkeerd?

[Shilizous 0]

1. zeer interresant

2. ik wil ook schimmelthee maken!

3. blijf je bevindingen posten hier, dan kan ik (en met mij vele) nog wat leren

 

cheers!

[whazzup 165]

Ik weet niet of je met bacto moet brouwens trouwens. Wat je absoluut niet moet doen met bacto is over je planten heenspuiten want die gaan echt kapot. Heb al twee keer per ongeluk een thee met bacto op mijn plantjes gespoten en dat vonden ze niet lekker. Kijk daar dus heel erg mee uit. Bodembacterieen horen in de grond. Ik lees ook veel dat bacterieën een korte kweekduur hebben (denk meer in uren) en schimmels een lange. In ieder geval zou ik bacto niet een paar dagen laten meepruttelen. Er zit trouwens wel weer humuszuur en kelp in

 

Ook mycorrhizae vinden het niet zo heel erg lekker in het water. Die kun je ook beter in het substraat stoppen in plaats van aangieten.

 

Normaal zit er naast compost en melasse ook meestal kelp en humuszuur bij een thee. Wormenmest is toch wel wat anders dan compost overigens, wormenmest is niet gecomposteerd. Ik zou daar eerder een product als perfect start van Sannie voor gebruiken, dat is een gecomposteerd materiaal met een hele hoge count gekweekt bodemleven van een behoorlijk stabiele samenstelling.

 

Hier nog wat overzichtelijk leesvoer

[Doc 12]

Zover ik het begreep gebruik je compost als je stimulatoren wil brouwen en wormenmest als je meer npk wil krijgen.

Zeker de pure zwarte wormenmest staat er om bekend heel erg geschikt te zijn bij thee brouwe.

Dat zie je aan het Vermaplex product waar veel mensen mooie dingen van gezien hebben.

Ook combinaties worden gebruikt.

Het aantal recepten die ik vindt voor thee is eindeloos.

Het is zoeken naar het beste recept met de producten die je om je heen kan vinden.

[Nighthaunter 1]

IK gebruik mn thee nooit voor over mn planten.

Gaat altijd in mn substraat.

De keren dat ik met bacto en mayan micro heb gebrouwen gaat het schuimen iig

Mishien dat sannie het weet of het goed is?

[polletje 21]

denk dat je gelijk hebt W, die perfect start om te vermenigvuldigen en honey als voeding voor de bacterien en mayan als katalysator

dan heb je in iegergeval een goede bacteriebom voor de groei...

 

het leuke is dat je voor de bloei een mooi recept moet uitvinden, heb ik dus wat te klooien

als je nou gewoon biovoeding neemt en dat in dat ding gooit, dan de bacterien er mee laat spelen, is het dan zo dat de bacterien de voeding al klaarmaken voor de plant?

 

het principe van bacterien vermenigvuldigen snap ik nou, maar de P en K-tjes klaar maken zodat ze klaar zijn om opgenomen te worden voor de plant is even een stapje verder om te onderzoeken hoe dat precies gaat.

 

had laatst met sannie er over dat goed organisch kweken moeilijker is dan mineraal, nu snap ik een beetje wat hij bedoelde.

wel leuk dat ik nog zoveel te leren heb, door dat ding te kopen verdiep ik me nu in dingen waar ik daarvoor niet echt bij still stond

 

die planten gaan zo diep met dingen en er hangen zoveel haakjes en oogjes aan, dat is niet te omvatten, gelukkig heb ik de tijd en de zin om er voor te gaan

 

soms denk ik echt dat ik t begrijp en dan n nieuwe invalshoek en sta weer met beide benen op de grond, IK WEET NOG NIETS !

 

ps. zijn er meer mensen geinteresseerd in een cursus microscoop met info over een xtractor en brewer?