| Abstract |
This grant was established to design a terrestrial model ecosystem that was simple, inexpensive, and suitable for examining the total environmental fate of radiolabeled pesticides in a soil crop model e.g. soil-corn or soil-soybean. This was accomplished with the practical development of a system in which corn or soybeans are grown on 3 kg of typical Illinois soil types contained in a 19 1 wide-mouth glass carboy fitted with airtight lid and impingers to sample pesticide content in aspirated air, and a bottom petcock to sample leachate water. The units are housed in an environmental growth chamber under 12 hours simulated daylight, at 26C. Emphasis was placed on tracing the fate of the pesticide chemical and its degradation products in soil, air, water, phytoplankton and in the major food chain organisms of the model ecosystems, e.g. Zea mays, Glycine max, Lumbricus terrestris, Limax maximus, Armadillidium vulgare, Estigmene acrea, and Microtus ochregaster in the soil-plant phase; and Daphnia magna, Culex pipiens quinquefasciatus, Physa spp., and Gambusia affinis in the leachate water. The 14C-labeled pesticides examined included DDT, methoxychlor, aldrin, dieldrin, fonofos, phorate, parathion, methyl parathion, simazine, trifluralin, 2,4,5-T isooctyl ester, hexachlorobenzene, pentachlorophenol, pentachloronitrobenzene, and captan. Detailed summaries of their fate and degradation, based on more than 20,000 analyses, are presented. |
