3 Part Series on Compost Tea: General Definitions

We are starting a three part series on compost teas , specifically vermicompost teas. In this blog we will start with some general definitions.

One of the basic principles of the modern organic agriculture movement is that the biology of the soil has to be managed through the use of organic matter. Soil organic matter can be increased by the use of cover crops and the addition of compost and vermicompost. In addition to increasing soil organic matter, the diverpostse microorganisms present in compost and vermicompost can stimulate growth of plants and also can suppress plant diseases when used as soil amendments.

In the last three months we have increased our use of compost teas at Frog Hollow Farm. Compost tea can be defined as follows: thermophilic compost, vermicompost and old growth forest soil humus is mixed with water and is brewed at ambient temperatures for 24 hours. To establish a production system with a consistent outcome, we manage the following variables:

*Compost sources: thermophilic compost and vermicompost is made on-site at the farm with known starting materials and is characterized by excellent biology

*The old growth humus is derived from Alaskan forests and is rich in beneficial fungi 

*A biological assessment of the compost is made by MLF Soil consulting before brewing 

*The brewing system with constant aeration has been designed by experts in the field

*The brewing protocol has been formulated by experts in the field and this includes the use of supplemental additives

Why does Frog Hollow Farm use compost teas? Compost teas are used to speed up the decomposition process in thermophilic compost windrows and they can also be used to increase the fungal component of the compost. Compost teas are used as drenches in the soil to amend soils that are problem areas and need a quick short term fix (which in the long term can only be improved by the application of solid compost). Compost teas are used as foliar sprays to keep the ecosystem of leaves healthy or to fight certain infections that can be persistent in the orchard. Brown rot and powdery mildew are examples of pathogens encountered at the farm. Solid compost cannot be applied to  leaves and so compost teas are the solution.

Compost, vermicompost and compost teas have been shown to improve soil organic matter. Disease-suppressive composts and vermicomposts have also been well documented in the scientific literature. We will summarize these experiments in future blogs and also discuss some inconsistencies. The following scientists have been leaders in this field of biology and some of their works will be cited: Dr. E. Ingham(Soil Foodweb Inc), M. Slaughter (Earthfort), Dr. C.A. Edwards (The Ohio State University), Dr. N. Arancon (University of Hawai, Hilo), Dr. A.L.H. Jack(Cornell University).


A note about cover crops at Frog Hollow Farm:

As mentioned in a previous blog, MLF Soil Consulting is trying to introduce Melilotus indica or sour clover (but this is not a scientific name and this is not a real clover). This plant is a nitrogen fixer and also is reputed to deter gophers (anecdotal evidence). In our first experiment, only one plant survived out in the orchard (nothing to write home about) but  it survived! We knew the reason for the poor showing: plants need water!

In the last three weeks, we planted some extensively scarified seeds under some peach trees and there are about 200 seedlings growing. For the first two weeks of growth the watering was intensive and that helped. To those who indulge in pleasant aromas, sour clover sproutings seeds give off a very sweet honey-like odor and the leaves of the young plant taste sweet (and numb your tongue).


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