Composting has been implicated in the degradation of various pesticides. A pilot study was designed to determine if degradation curves could be developed for the following pesticides: DDT, Kelthane and Aldrin. These pesticides were added to soil at the level of 60, 1200 and 8 ppm respectively and placed in 18.93 liter containers with 30% cow manure and a consortium of soil microorganisms with the dominant species being Pseudomonas fluridans , Bacillis subtillis, and Aspergillis sp. The test was conducted at ambient temperature ranging from 4.5 to 21 C. Each lot was mixed, sampled and a fresh source of soil microorganisms added weekly. At the end of five weeks, levels were reduced by: DDT 86%; Kelthane 55% and Aldrin 88%. Degradation did occur at ambient temperatures of 4.5 to 21 C. A greater degree of degradation would be expected at higher temperatures found during normal composting of poultry litter and mortality.
A second experiment involving the normal composting process using macerated broiler mortality is being conducted. In this experiment, we obtained some plastic commercially available minicomposters. These minicomposters have a maximum capacity of .65 cubic yard or about ½ cu meter of material. We consider this amount to be about the minimum for good composting activity.
We started the project by making a compost with 841 pounds of macerated broiler chicken, 860 pounds of broiler litter, 411 pounds of green waste, and 492 pounds of water. After one week of composting, we divided this compost into six units weighing 328 pounds each and placed them in the minicomposters. We have a pesticide control with DDT, kelthane and princep in it. We have a minicomposter with DDT, one with Kelthane, and one with princep. There is a bunker C control and a bunker C minicomposter. We used 10 ppm of DDT in the control and contaminated bin. For kelthane and princep we used 100 ppm and for both the contaminated bin and the control, we used 2500 ppm. All bins except the two controls have the above mentioned soil microorganism consortium (SMOC). One premise being evaluated is the ability of this particular SMOC for degrading pesticides and other contaminants such as oil.
So far with the second experiment, it is difficult to measure the ability of the compost process and/or SMOC to degrade pesticides and oil. At this point, it looks like the most difficult problem to overcome is the development of a sampling technique. The numbers are so small and the variation so large that it looks like it will either degrade it entirely or it won't.