Compost Brewers
Article taken from the "Company File" section of the T&CVA Newsletter Vol. 9 No. 31 - 2003
"Compost Brewers", based and run at the offices of Hall, Plank, Robinson Ltd., Agricultural Merchants in Theaie, near Reading, have as their motto - "Restoring Harmony to Soils'. Michael Harrington is a director and an arable specialist. Compost Brewers was set up because of his interest in organic systems and invigorating soils that had been destroyed by modern farming systems. He had the idea of producing a small brewer for his own use, but word got out! He found that it was a great way to introduce people to how soils and plants function. Given that understanding then there is a better chance in managing plants and soils rather than relying on the short term chemical fix.
He writes: "Some people felt that agriculture in the 1950s took the wrong route with the onset of chemicals and synthetic fertilisers. The principle of the ACRES organisation is to promote natural farming systems which is the point at which I was introduced to 'Compost Teas'. As regards vineyards, although we have had success with compost liquids, there is an issue that I wish to explain. Compost liquids should not be regarded as a straight replacement for chemicals, it is part of a system that as a whole works but if any part of the system fails down then disease can become evident. Management and siting of the vines is very important. If vines like Madeleine Angevine become too thick, a micro-climate can occur which increases the risk of infection so vine management is important. Nutrition plays a big part in disease resistance because if a plant is not healthy, it will become prone to disease. In fact no different to ourselves. If the management and nutrition of the vines is good then compost liquids seem very effective. In fact the same is true of chemical systems but I believe that our reliance on these chemical systems has become so dominant that we perhaps do not pay enough attention to these other issues. Compost liquids to date I believe have been as equally effective as the current protectant sprays. Although this year (2002) we have had extremely high disease pressure and downy mildew is evident on most if not all vineyards. In these situations we would recommend returning to Ridomil to contain the problem and then starting again with the compost liquid to rebuild the biological barrier.
Chemicals are not the answer on their own, they should be part of an integrated system to be used when necessary not as a matter of course as has been the case for the last 30 years. Agriculture including the wine industry has serious problems from the effects of the overuse of chemicals, not that many will acknowledge the problem. They only acknowledge that chemicals do not seem to work very well anymore."
What is compost tea? Compost tea is a water extract of compost that is brewed, or in other words the organisms extracted from the compost, the bacteria, fungi, protozoa and nematodes were given a chance to increase in numbers and activity using the soluble food resources and nutrients present in the water. An enormous diversity of these organisms should be present, depending on the quality of the compost. It is this huge number of organisms that occupy the leaf or soil that then dominate the surfaces inhibiting disease-causing organisms from establishing. The principle highlights the dichotomy between organic and chemical practices in agriculture. Chemical pesticides kill everything, both pathogenic and beneficial organisms. The principle is, that when compost tea is sprayed onto a plant, it encourages the beneficial organisms to form a physical barrier against the pathogenic ones. Many food producers cite broadly parallel scenarios, e.g. a totally sterile soft cheese offers a more favourable environment to pathogens than a 'five' cheese with the latter having beneficial organisms which provide competition. Additionally the compost tea also
- provides plant food which aids healthy plant growth,
- strengthening the plant's defence systems and
- the addition of beneficial organisms to the soil will help the recycling of organic matter improving soil structure etc.
Dr. Elaine Ingham, of Oregon State University, has found that plant roots colonised by soil flora and fauna are more resistant to pathogenic attack.
The complexity of the soil food web is not fully comprehended and is an area of increasing research. It is estimated that one gram of desert soil will contain about 6,500 bacterial species; one gram of garden soil about 18, 000; one gram of mature forest soil approaching 50,000 species. A near symbiotic relationship is postulated between the plant roots and the soil microbes. Molecules released by the roots providing food and growth stimulants for the microbes. These in turn suprly nutrients back to the plant and produce chemicals which inh -- t the growth of pathogenic organisms in the soil surrounding the root area. It is believed that microbial populations will develop which favour the plants growing in that soil. This could explain some aspects of crop rotation and crop failure. It could also explain the previous difficulties of introducing pines into Puerto Rico. Attempts to introduce these trees never progressed beyond seedling stage until the soil in Puerto Rico was inoculated with soil from pine forests. Research from South America also suggests that the early stories of large native populations were not tall tales told by early Hispanic explorers. Archaeological evidence has been found of an extensive and complex agricultural system probably sustained by a highly developed system of soil composting.
Enough of background - let us get down to practicalities. There are two parts to the production of compost tea; first make your compost, then make your teal The microbial organisms present in the compost will be largely determined by the mix of organic material used, e.g. changing the proportion of woody and greenplant material will affect the balance between bacterial and fungal populations - a higher woody content will tend to produce more fungi. Control is important during the composting process to ensure that
- the temperature is sufficient to kill any pathogens;
- there is sufficient oxygen for aerobic organisms to grow.
Once the compost is ready then the process is similar to making a cup of tea - if on a larger and sometimes more sophisticated scale. A number of factors will influence the quality of the compost tea including the water used, the type of 'tea bag', aeration, balance of compost and water, brew time and the environmental conditions.
Research work carried out in America suggests that it is important to match the type of compost tea to the types of plants and soil.
Two Oxfordshire vineyards that are quoted in Compost Brewers newsletter as using the treatment with beneficial results are:
- Hendred Vineyard, where for the first time the Seyval Blanc did not need a chemical fungicide for downy or powdery mildew.
- Corner House Vineyard where the treatment was carried out alongside conventional chemical treatment. It is reported that the health of the plants treated with the compost liquid was far better.
For further information:
Compost Brewers Limited. 42a High St., Theale, Reading Berkshire RG7 SAN
Tel: 0118-930-6464
Fax: 0118-932-3746
website: n/a
ACRES (USA) website: www.acresusa.com or www.soilfoodweb.com
[Editor's note: Company File is a feature designed to give basic information about relevant companies to members. It should not be taken as an endorsement of that company or its products/services.]