Compost Teas Show Promise
Ongoing research seeks recipes to bring teas mainstream
The Rodele Institute's 333-acre farm is home to a long-term field trial with six different treatments replicated four times.
It is our job to put life into the soils; not to destroy what we hate, but to build upon what we love, insists Dr. Elaine Ingham, chief scientist, Rodale Institute in Kutztown, Pa.
Ingham says that overburdening turf soils with inorganic chemicals, although effective in the short term for greening grasses and eliminating many unwanted weeds, is causing a toxic residue buildup that ultimately requires more and more applications for fewer positive results while further weakening soils.
Ingham and her team are doing research on "compost teas" and she is confident that these fortified organic teas are a healthy way to achieve beautiful lawns. Teas are the liquid extracts of solid compost, to which foods are added to help grow the organisms needed as the compost is aerated through a water-flow device over a set period of time. The science looks promising, and Ingham and the Institute are bursting with enthusiasm for the various studies and anecdotal evidence they find throughout the world.
The teas are sprayed onto the surfaces of plants and turf and are dispersed into the ground allowing beneficial microbes to get to work almost immediately. "There is some reporting that compost teas reach turf roots and affect growth in as little as three hours as opposed to as long as three days for solid composts put on the soil surface," explains Ingham.
Mother Nature knows best
Ingham continues, "It really does take quite a bit of audacity to believe that after about 4 billion years, suddenly Mother Nature needs us to apply man-made chemicals into the soil to help her out."
Dr. Elaine Ingham, chief scientist, Rodale Institute, researches ways to improve soil biology sans man-made chemicals.
Photos courtesy Rodele Institute.
The philosophy at Rodale and her personal studies have led her to conclude that both horticulture and agriculture need to get back to basic soil biology; improve the organic matter within soil, build the system to select for the plants we desire, instead of attempting to kill the weeds and pests that are sometimes found in soils. In her view if turf professionals infuse the ground with proper amounts of organic materials plus bacteria, fungi, protozoa and beneficial nematodes through the proper use of composts, they will improve the soil and the earth itself will become healthy enough to fight off the various vexations that might burden it.
Rodale Institute is a nonprofit research and educational organization funded by federal grants and endowments, but is not a typical "think-tank." Here the researchers got down and dirty with the soil. Its purpose is to champion organic farming and horticultural efforts throughout the world. With a budget exceeding $20 million and assets of over $10 million, their outreach is felt in many parts of the world of soil sciences.
If the compost is not carefully prepared, tested and monitored then what results is not truly organic compost, says Dr. Elaine Ingham. It's the quality of the compost that matters.
Liquid versus dry
Although Ingham is in favor of applying composts in either dry or liquid form, she says test results demonstrate several benefits of teas over dry applications. These include the need for fewer applications, less amounts of composts needed, improved plant disease suppression and improving soil structure and plant vitality by allowing a large and diverse community of microbes, humic acids and other chemical nutrients, such as carbon and nitrogen, to support the soil and promote healthy plant growth.
However, some studies report little advantage in teas over dry compost applications. The problem is not in the science, the problem is in what Ingham defines as developing initial healthy composts. "If the compost is not carefully prepared, tested and monitored then what results is not truly organic compost. The quality of the tea is only as good as the composts used to make it. Compost is the source of organic matter and organisms for extraction, so quality is very important.
"In addition, these huge composting facilities selling bulk compost to professionals don't measure the life in the organic materials when they receive it. These facilities were designed to eliminate the problems associated with handling huge amounts of yard waste into public landfills by reducing its volume, without any emphasis on producing a quality product. Their purpose is not to produce composts, they're focused on the municipal problem of landfills filling up too fast."
Ingham suggests, for best results, the waste industry needs to understand compost and composting to develop amendments that will benefit the soil and not harm plants. The formula Rodale has been working with for a number of years includes: approximately 30 percent green materials such as grass and vegetable waste; 10 percent quality high-nitrogen material, such as peas, bean, alfalfa plant materials or manure; 50 to 60 percent woody materials such as wood chips (careful to let pine and walnut lose the strong smells before use), paper, cardboard, dry brown leaves, stalks of plants, etc. Be careful of sawdust because it is hard for air to move through finely ground materials. When the proper mix is assembled, heat will be generated within 24 hours, and then, if the pile generates enough heat, it needs to be turned when it reaches 160 to 165 degrees Fahrenheit.
Handle the compost during the composting process. Ingham continues, "For instance, measure the middle of the composts pile for proper temperature of at least 131 degrees for 15 days and turn the pile at critical times to manage microbiological activity and insure the right amounts of 'brown' (woody material) and green materials are fueling the process."
Aerobic microherd (microorganisms that breakdown organic materials) populations prevent offensive smells in compost piles, compost teas and the soil. Aerobic microherds also breakdown poisons and prevent pathogens from growing, allowing the end product to be safe for further use in potting mixes, vegetable beds and the production of aerated compost teas.
Ingham says that properly made compost contains highly beneficial organisms, humic acide and organic materials that benefit plants and build organic lawns. She suggests that the normal four-season approach with inorganic chemicals can be done much more effectively and much less expensively with tea applications combined with dry composts applications, one to two of each a year.
"The important part about compost, compost extracts and compost tea is the set of organisms in the compost," she clarifies. "Extraction and brewing just make it easier to apply the organisms and the soluble organic matter to the soil or onto the foliage. It is the life in the compost that is all important."
Ingham further explains that a soil sample is the ideal place to start, and if results show organisms (types of bacteria, fungi, protozoa or nematodes) are lacking or harmed they should then be added. If it is determined that no harm was done, adding better foods will improve upon the health of the microbes.
The Rodale Institute offers a course "Life in the Soil" covering all aspects of developing organic soil, including making proper compost and compost teas. The course costs $1,370, but is free to lawn care professionals and is intended to teach and instruct professionals in the biology of soils and lawn care not based on synthetic chemicals.
"Our program is structured in one three-day class that will build the learning foundation followed by a day to teach composting, a day to teach compost tea/extract and a day to teach microscope use and organism identification," says Ingram. "Each one of these classes builds upon knowledge acquired in the previous class for a comprehensive understanding of complex forms of life in the soil and their importance."
The Institute's 333-acre farm is home to an ongoing 33-year field trial with six different treatments replicated four times. Organic practices build organic matter, sequester carbon and eliminate the use of synthetic chemicals and fertilizers. The results of this 30-year study have shown that organic yields match conventional yields and organic farming systems are more profitable than conventional.
Ingham is confident that this same soil science will prove equally effective for turf growth. "It's just a matter of building the soil biology to produce what we want and not killing what we don't need," she says.
Mike Ingles is a researcher and writer who lives and works in Columbus, Ohio. Contact him at firstname.lastname@example.org.