Cornell Waste Management Institute

Compost Marketing and Labeling

Agricultural Compost Marketing and Labeling
Project Summary
November 2001

The overall goal of the New York State Energy Research and Development Authority (NYSERDA) supported Compost Market and Labeling Project is to expand the market for agricultural composts in order to help manage manure and make farms more profitable. To achieve this, either a label or a seal-of-quality is being considered to help consumers. In order to determine the needs and wants of the compost consumer, Cornell Waste Management Institute (CWMI) in 2000 conducted surveys, for both home gardeners and industry-users (mainly vegetable growers). An examination of bags in which composts are marketed in New York State was conducted to see what information was made available to consumers and how it related to the information which the consumers want, as ascertained through the user surveys.

Information about the current composting practices of 44 New York State farm operations was collected in 2000 by CWMI in order to determine main sources of feedstock, composting methods and how the finished product is being used. An additional farm survey was conducted with 20 New York State farm compost managers. The prime focus of this intensive survey was to gather information in regards to the testing in which these farms are involved and/or interested in having implemented.

In conjunction with the surveys, CWMI and Woods End Research Lab (WERL) investigated existing and developing programs from around the U. S. and Europe for testing and labeling composts, to consider their relevance to a New York State label/seal program. A summary of all of these results can be found on the CWMI web site at:

Results were discussed in stakeholder meetings. Compost consumers and industrial-users, along with stakeholders and compost managers expressed interest in either a label or seal of quality as a tool for marketing agricultural composts. Knowledge of the characteristics and quality of agricultural composts was determined to be a prerequisite to developing such a program. Thus, CWMI initiated a preliminary compost analysis phase. The primary goal of this pilot phase was to develop sampling protocols and parameters for a larger investigation. Several samples taken from the same piles of finished compost over several weeks were analyzed to determine whether sampling could be effectively done by the composters vs. trained CWMI staff, to look at the potential variation over a short time period, and also to evaluate a range of parameters to consider for inclusion in the subsequent testing. Among these parameters were pH, N-P-K, weed seeds, organic matter, metals and pathogens, which were analytes of interest to compost consumers and industrial-user as ascertained in the surveys. In this phase, 7 farms actively composting were recruited. Sampling instructions prepared using a combination of WERL and US Compost Council TMECC sampling guidelines were provided for each farm. Composite samples were collected at three times. For the first set, two samplers (CWMI and farmer-composter) sampled the finished compost. Two weeks later, CWMI and the farmer-composter took samples. Finally at a slightly later date, the farmer-composter took two more samples of the same pile. Where on-farm bagging of composts was practiced, four samples were drawn across a single batch of compost bags.

Analysis of the results from this phase revealed that the sampling directions provided to farm compost producers were adequate to produce similar results between farm and CWMI sample takers. However there were two major concerns that spawned the need for additional studies. The project team (CWMI, Cornell Dept. of Biological and Environmental Engineering, WERL and NYSERDA) was concerned that the results obtained from the first testing phase did not represent the possibility of variation of results due to the depth at which the sample was taken within the pile. Also, due to elevated levels of some metals in some composts, further analyses were conducted to include additional heavy metals addressed in the EPA 503 sludge rules and NYSDEC 360 rules.

All of the metal concentrations tested for in the initial phase were well below EPA 503 and NYSDEC 360 standards. Iron (Fe) tested high in several composts, which can be a positive for selling agriculturally produced compost. Conversely, Copper (Cu), which, though below regulatory standards, showed elevated levels in some composts, could, with repeated applications, produce a soil with phytotoxic qualities. Therefore, as a result of this project, investigation into the cause of elevated Cu levels is underway. Pro -Dairy has been informed of the high levels of copper found on these farms and is looking at Cu use. Arsenic levels were elevated in a couple of the composts. Questions concerning on farm management practices of CuSo4 hoof dip, potential sources of arsenic (including possibly water supply) and regarding use of herbicides and pesticides will be added to the surveys for the farms participating in the next phase of this project.

Farm compost piles are often irregular in shape, dissimilar in dimensions and sometimes very large. Therefore, prescribed sampling procedures may not adequately reflect intrinsic problems of representativeness. Through additional investigation, this project examined the variability of test data in dependence of depth into pile. The study was designed to evaluate how different characteristics of compost vary with depth of sampling in large piles. The depth results showed there is relatively small variances within the piles with respect to depth. Weed seed showed the most variation with respect to depth. Weed seeds were found in higher numbers at the surface which is likely due to the fact that many weed seeds are transported through wind current thus collecting on surface.

Analytic results of this testing are appended.

Johnes, a bacterial wasting disease in ruminants, is of great concern to the dairy industry. Since bacteria can be transmitted though manure of infected cows, a compost investigation was designed to investigate the degree to which active composting can reduce or kill Mycobacterium paratuberculosis, the organism that causes Johnes Disease. The controlled experiment was conducted on Cornell's compost pad. Manure, secured from a Johnes free farm, was inoculated with infected manure from a heavily shedding cow. A sanitized loader was secured for the initial mixing and weekly turning that was done by Cornell Farm Services. Daily temperatures and weekly samples were taken.

The Cornell Johnes lab is running the Johnes analyses on all samples. Each test procedure takes a minimum of six weeks. Results are not yet available. The samples have been twinned and the second sample sent to WERL. Follow up testing will also be done on some farms included in the next phase of the project.

In the future, the Market and Labeling Project will begin testing on approximately 30 farms within New York State. These 30 farms will represent 3-4 different compost source material types and compost processing strategies. Samples from approximately 12 farms taken before winter will be analyzed for the following parameters: density, % total solids, % organic matter, water holding capacity, pH, conductivity, inerts, C:N, Solvita maturity, Solvita ammonia, % germination, % plant-growth, fecal coliform, weed seed (basic viable), total-Kjeldahl-N, nitrate, nitrite, carbonates, % phosphorous , %potassium, calcium (Ca), magnesium (Mg), arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), and zinc (Zn). WERL is testing composite archived samples from the 7 pilot farms for chromium (Cr), nickel (Ni) and minerals calcium (Ca) and magnesium (Mg). They will be included in this list of analytes if they are found in archived samples at significant levels. Testing for lead (Pb) and mercury is not proposed since levels were very low in the initial 7 composts tested. Johnes analysis will be conducted on samples where need is indicated. Testing for herbicides and pesticides is not planned for this project.

a. Survey data located
b. Table of standards/guideline/specs
c. Initial sampling of 7 farms ­ attached.

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