Composting and organic farming have had parallel growth in British Columbia. Both are ancient arts in the production of agricultural crops that have experienced a dramatic increase in interest and employment since the mid 1980’s. Composting has received higher acceptance and use during this period because of its application beyond the rigid rules of organic production standards. The use of composts is one of the cornerstones of organic production. Composting, crop rotations, bio-diversity, and restricted use of chemical intervention are considered the major principles around which organic agriculture is based.
Organic farms. In recent years as the size of the organic farms has increased so has the need to develop more mechanized methods of on-farm compost production. More commonly the organic farm has turned to the purchase of off-farm produced compost. The demand of mainly organic nitrogen sources for organic farms has resulted in the farmers need to go further distances to obtain compost materials for their farms. The increased dependency of organic farms for outside sources of compost has resulted in heightened concern about what is in these materials.
CURRENT STANDARDS IN BRITISH COLUMBIA
The COABCi lists compost as an allowed input and describes it as follows. “Composting refers to the carefully managed process by which organic materials are thermophilically digested. In order to effectively stabilize the nutrients in compost, reduce some pesticide residues, and kill weed seeds and pathogens, aerobic compost piles must reach a temperature of 55 – 60 degree Centigrade for a period of several days and then finish decomposing for about 6 weeks. Compost should remain moist but not water logged for the whole decomposition period. Written documentation of the source of off-farm materials is required. Organic waste material derived from industrial processing including abattoir waste, yeast fermentation waste, whey, hatchery waste, fish farm wastes, mushroom compost, and paper and wood products are regulated products and documentation and/or appropriate laboratory analysis for the absence of contamination by materials prohibited in these standards is required. Acceptable feedstock include animal manure, by-products of the processing of agricultural commodities and source separated yard debris. The following are prohibited in compost: sewage sludge, synthetically fortified compost starter, glossy paper, and colored ink. Paraffin from waxed cardboard cannot exceed 0.75% of total feed stock by weight. Growers should obtain a list of the main ingredients in any purchased compost not reviewed by OMRI.
It is required to have:
a.Written documentation of source of off-farm materials used in on-farm composting activities.
b.Written record of ingredients of any purchased compost used on the farm.
c.Composting activities shall conform to the Agricultural Code of Practice and the Waste Management and Health Acts.
d.Aerobic compost piles must reach 55 – 60 deg. C for several days and be finished composting for about 6 weeks.
e.Growers should obtain a list of the ingredients in any purchased compost not reviewed by OMRI.
Regulated organic waste materials listed are:
a.Abattoir waste
b.Yeast fermentation waste
c.Whey
d.Hatchery waste
e.Fish farm waste
f.Mushroom compost
g.Paper, cardboard, and wood products. Cardboard must not be impregnated with fungicides.
h.Paraffin from wax boxes must not exceed 0.75% of total feedstock by weight.
i.Organic waste material not from approved sources can be subject to appropriate laboratory analysis for absence of contamination by materials prohibited in these standards.
Prohibited materials listed are:
a.Glossy paper or paper with colored ink.
b.Sawdust or wood chips containing treated wood.
c.Synthetically formulated compost starter.
d.Septic tank waste.
e.Sewage sludge.
In the early stages of the development of the organic industry there was considerable scrutiny of the compost used on my farm. We had to have our bedding of wood waste products tested for PCP’s and had to have these tests followed up with tests for PCP’s in the manure, finished compost, soil, and crop residue. I have had to weight the waxed boxes going into my compost to ensure that the weight did not exceed the 0.75% requirement. However in recent years with the rapid increase in the organic market and the introduction of more large-scale farms into organic production the requirement for testing has largely been ignored. I believe we are ignoring what is in the composts going onto our farms at our own peril.
PROPOSED NATIONAL ORGANIC STANDARD
The federal government in conjunction with the organic industry is pushing hard to have a national system regulating organic production by the end of 2005. It is worth having a look at what this national standard will say about composting. The proposed definition of compost is “a stabilized product of controlled decomposition of an appropriate mixture of nitrogen and carbon bearing materials that have been piled, periodically mixed, subjected to heating above 55 degree C, then cured for an extended period of time (in a process designed to mitigate environmental damage) to produce humus as a soil amendment or fertilizer.
The proposed national standard stipulates:
a.That the production of compost must follow federal and/or provincial compost standards for maturity, foreign matter, trace elements and pathogens.
b.The use of off-farm sources of manure is discouraged.
c.Municipal sewage sludge is not permitted as a compost material.
d.All sources of manure from non-organic enterprises shall be composted before use on the enterprise to maturity for a recommended period of six months. Compost may be matured in shorter time periods, however, composting plans must be approved by a certification body to ensure that the appropriate process for short-term composting and determining the maturity of compost will be completed.
e.Off-farm sources of compost shall only be used with the approval of a certification body. The certification body shall reserve the right to prohibit the use of municipal, industrial, commercial, or institutional composts that otherwise have achieved an unrestricted use classification by federal or provincial compost quality standards, based on an analysis by an analytical laboratory of compost or feedstock components that do not comply with this standard.
f.Composts from non-organic and organic sources whether composted on or off farm are listed as permitted in put with some restrictions.
The definition is much tighter than that by the COABC but the standard appears to be even looser than that of COABC because the requirement for testing has been dropped.
RECENT CONCERNS ABOUT NON ORGANIC SOURCES OF MANURES
The recent outbreak of Avian Flu in the lower mainland of British Columbia and the ongoing concerns regarding mad cow disease have high lighted the differences between organic farming and conventional farming. The Avian Flu was almost entirely confined to the conventional farm industry where the birds were confined within high-density barns. The concern over the spread of mad cow disease is the feeding of animal by-products to cows. This is a practice that has been prohibited in organic standards from the outset. These recent news-grabbing problems have raised the concern of cross contamination onto organic farms with the use of manures from conventional farms. Composting may aid in the elimination of the specific pathogen but one has to question what else might be involved in using these materials.
A far greater concern for organic farms should be that surrounding the increased use of genetically modified organisms (GMO’s) in conventional agriculture. The near 100% conversion of the canola crop to genetically modified varieties and the development of genetically modified soybean and corn varieties is sure to cause contamination of all animal feeds used in conventional production.
The fumigants, fungicides, rodenticides, and antibiotics used in animal production are bound to contaminate the manure sources. Proper composting will break down many of these materials to benign organic compounds, as it will kill most pathogens. However as an organic community we are concerned about the rapid development of new compounds that are being developed every year. In Vol. 5, Issue 1 of the OMRI Update it was reported that “Clopyralid, the active ingredient in a number of widely used herbicides, is a persistent chemical that does not break down in the composting process.” There is little hope that the organic certification bodies or even OMRI can keep up with the development of potential contaminants that are in conventional manures.
CONCLUSION
Conventional manures, as long as they are properly composted, remain an important source of nitrogen, organic matter, and micronutrients. Even while raising concerns about the possible contamination OMRI has not had the resolve to list them as prohibited on their lists. It is prohibited to use manures from conventional sources composted or otherwise in certified organic production in Europe where concerns regarding the ethical treatment of animals and diseases such as mad cow have been heightened. In North America the major concern is the availability of organic nitrogen sources and most major certifiers do not prohibit it. Smaller organic certifiers with higher ethical concerns have prohibited the use of manures and composts from conventional sources (the Island Organic Producers Association is one of these). It is my belief that they will eventually be banned but the need for alternative sources must be met.
The requirement for testing will likely become more stringent in the next few years as the awareness of the differences between organic agriculture and conventional agriculture become more apparent. In any event it is important to identify the sources of materials that were used in making a batch of compost for sale into the certified organic system. A complete nutrient analysis should be given and should include the salt content.
There is a need for strict avoidance of urban wastes, heavy metal contamination, synthetic compost starters, and contaminated wood waste and paper products. These are in the current standards largely because they were of a concern at the time of the writing of the standard in BC. If the standards were written in BC at the present time I have little doubt that the standards would make more explicit references to the contamination of manures with GMO’s, the concern over disease transfer, and the ever increasing complexity of chemical use in conventional animal production.
Proper composting is a viable and valuable way of breaking down many organic compounds and is an effective way of destroying disease organisms and other pathogens. However, the increasing concentration and density employed by conventional animal production and the rapid approval of products used in conventional agriculture are raising serious concerns for organic agriculture.
Prepared by Fred Reid
For
COMPOSTING MATTERS
February 23 and 24, 2005
