Vermicompost Teas
Suppress Parasitic Nematodes and Arthropod Pests. 
(hint:  aphids and spider mites are arthropod pests)

The availability of a wide range of commercial tea brewing equipment has the use of teas expanding.  More and more people are trying their hand at brewing tea in order to organically attempt to solve a pest problem or nutrient deficiency.

These teas are used by organic gardeners and farmers to promote plant growth by controlling the plants environment. Tea can be applied as a soil drench and foliar spray. Uses are increasing as effectiveness is gradually be established.  More reliable sources are popping up and offering proof of successes being achieved by using these teas.

The Ohio State University, with Clive Edwards in the lead has shown that agitation or aeration during production of vermicompost teas is absolutely necessary if teas are to be effective. Further research is under way into how well vermicompost teas work. Evidence indicates that the microbial activity, diversity, key nutrients and enzymatic activity from solid vermicompost does indeed make it into the teas.

Experience has proven that the sooner a vermicompost tea is used after brewing the more effective it is in having an influence over plant growth and in suppressing pests and disease. The longer the tea goes without aeration and food the beneficials in the tea begin to die off.

Controlled experiments were done assessing the effects of vermicompost teas on plant parasitic menatodes and arthropod pests. It has been proven through these tests that vermicompost teas showed specatcular results and were very similar to those experiments that used solid vermicompost.

This next statement is taken directly from article written for BioCycle December 2007, Vol. 48, No. 12, p. 38 by Clive A. Edwards, Norman Q. Arancon, Eric Emerson and Ryan Pulliam, authors from the Soil Ecology Laboratory at The Ohio State University in Columbus, Ohio.

"...aerated vermicompost teas suppressed the aphid populations significantly (P < 0.05) compared with the water control treatment whereas the aerated thermophilic compost tea had no significant effects on the aphid populations.
These results on the suppression of aphids and spider mites by vermicompost teas were very similar to those obtained from growing plants in the greenhouse in Metro Mix 360, substituted with a range of solid vermicomposts (Arancon et al. 2007). The suppression of aphids is particularly important since they are key vectors in the transmission of plant viruses. It seems clear that there is a good potential for suppression of arthropod pests by both vermicomposts and vermicompost teas using methods very acceptable to organic growers and farmers."

In other words,  tea brewed from compost from worms out-performed tea brewed from conventional compost in suppressing aphid populations.  In fact, the worm compost tea performed as well as adding vermicompost to the soil.

Dr. Clive Edwards is known to say that vermicompost will out-perform conventional compost every time because of the wide variety of beneficials present in the vermicompost compared to those present in conventional, thermophilic compost.

My personal recommendation for a small scale tea brewer:

Compost Tea

What is compost tea?  As it is with many things, it is many things to many different people.  What do you think compost tea is?

Is compost tea a fertilizer?

Not all compost tea is equal.

Way back in the "good ol' days" before electricity and the invent of chemical fertilizers and pesticides, the gardener/farmer had natural ways to coax the most they could get from the land.  Back then they'd throw a heap of manure in a bucket, add water and let it sit for a spell (usually 7 to 14 days) until the water was a nice dark "tea" color.  Over the years the art of composting was developed and instead of using manure, the finished compost was used to make a tea which, in both cases, was used as a liquid fertilizer.  The by-product of this method would officially be called "Compost Extract".

Take a leap forward to present day.  Soil health has become a science and along with that has been the development of the science of vermicomposting and the bacteria or fungal rich tea that can be produced from the finished product.  But in order to do that requires more than dumping some vermicompost in a bucket and letting it sit.  Likewise, the "compost leachate" that is the dark solution obtained from the bottom of a worm bin or compost pile is not even close to the same thing as high quality compost tea or AACT ( Actively Aerated Compost Tea) that the experts are referring to when they speak of Compost Tea.  Compost tea, in modern terminology, is a compost extract brewed with a microbial food source — molasses, kelp, rock dust, humic-fulvic acids are common ingredients. The compost tea brewing technique is an aerobic process that extracts and grows populations of beneficial microorganisms 

The experts will tell you the most valuable compost tea is one that has been brewed with an aerator and some sort of food source for bacteria.  Because that is what you should be growing when you brew compost tea.  The bacteria is what makes REAL COMPOST TEA a great value to the grower.

This is a relatively new field and there are many differing opinions, but there are a few facts that are hard to dispute:

Good compost is an absolute necessity - If you are going to brew a high-quality compost tea then you have to start with a high-quality compost.  You can only grow whatever you have present in your compost.  Therefore, if you are a professional grower, or if you are battling a particular problem you will want to know exactly what your have in your compost and you will want to have it tested.  But if you are just a gardener trying to improve on the health and productivity of your families crops then if you build a healthy compost with a variety of materials that should suffice.

A food source is essential - In order for your micro-organisms to grow in sufficient numbers there must be a food source.  The goal is to provide enough food to maximize your growth of beneficial organisms without over-producing and causing the tea to go anaerobic because the organisms use up all the available oxygen.

Oxygen - All living organisms need oxygen to live!  The organisms in your compost tea are no different.  If there isn't enough oxygen while you are brewing you will start growing anaerobic pathogens which are toxic to plants.  By keeping the oxygen levels high you are growing the good biology, which is what you want for your plants.

Is Compost Tea A Fertilizer?

It has been asserted that compost tea is a fertilizer.  Let's be clear that neither LCE (liquid compost extract) nor ACT (aerated compost tea) is a fertilizer in the traditional sense.  Both are biological, microbial stimulants with some nutritional value,  but NOT fertilizers.
 

You can add some organic fertilizers like fish hydrolysate to the teas if you are looking to do fertilization at the same time.

Client Corner    In the spring of 2004, Gus Wahner sprayed 1/2 of this cherry tree with compost tea. He used a mixture of 4-gallons of compost tea and 1 c. of fish emulsions. These are the results after only one spraying! This is a great example of beneficial microbes increasing nutrient cycling. At harvest time, you can see the difference. Yields were higher and leaf mass and health was also better on the sprayed side. In fact, much of the fruit is actually obscured from view by all the foliage on the compost tea side!    Gus runs Custom Composting Services in Hermiston, Oregon. He has been using compost tea for 3 years. Gus has been a proponent of organic practices and compost tea fits nicely into his program. You can contact Gus at gusatbiotea@aol.com or by phone at (541) 571-2300 for more information about his company or programs.

Not treated with compost tea. Treated with compost tea.

This is a real life application of a brewed compost tea shared with me in a newsletter from the company where I bought my compost tea brewer.

KIS® 5-Gallon Compost Tea Brewer $140.00

Individual Foods for your 5-gallon brewer ($1.50/bag)-These food packets come ready to use  with your own compost for one 5-gallon brew.

Re-usable mesh bags ($5.50-$16.00 depending on size of brewer)

Another Variety of Tea
 

Herbal Tea

Plant-based extracts—stinging nettle, horse tail, comfrey, clover. A common method is to stuff a bucket about three-quarters full of fresh green plant material, then top off the barrel with tepid water. The tea is allowed to ferment at ambient temperatures for 3 to 10 days.  It is recommended that you stir the mixture a couple times a day. The finished product is strained, then diluted in portions of 1:10 or 1:5 and used as a foliar spray or soil drench. Herbal teas provide a supply of soluble nutrients as well as bioactive plant compounds.
 

Soil Foodweb                            

Humus, and organic matter in all it's many forms provide both food and shelter to the large diversity of life that lives in a healthy soil.  The soil foodweb is the community of biodiversity that lives in this environment.

Compost tea production extracts the plethora of microbial life in a quality compost and multiplies it by providing food and oxygen.  This growth includes beneficial bacteria, fungi, protozoa, and nematodes.  When compost teas are used as a foliar spray these beneficial micro-organisms occupy spaces on the leaf that would be used by pathogenic organisms and the beneficials actually eat the "food" the pathogens would have had for dinner.  As a result the pathogens die from lack of food and living space.

Ideally, the compost tea contains both an abundance and a diversity of microbial life which perform different functions.

A great resource of information regarding compost teas and the effects on soil health can be found here:  

Notes on Compost Teas:
A Supplement to the ATTRA Publication Compost Teas for Plant Disease Control
Pest Management Technical Note
 

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Organic Conspiracies
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email me:  Christy@vermiculturenorthwest.com

 Christy Ruffner © VermiCulture Northwest 1997-2012