Crop Seedling Uptake of DDT, Dieldrin, Endrin, and Heptachlor from Soils1
- M. L. Beal and
- R. G. Nash2
In greenhouse experiments, soybean, wheat, corn, alfalfa, bromegrass, and cucumber seedlings took up various amounts of DDT, dieldrin, endrin, and heptachlor residues from five soils treated with 0.5 or 5.0 ppm insecticide. Residue concentrations in plants were usually well below the soil treatment rates, though endrin and heptachlor residues in alfalfa and bromegrass exceeded the treatment rate of some soils. The order of residue uptake in increasing amounts was DDT < dieldrin < endrin < heptachlor.
Correlations calculated between residues in seedlings and several soil characteristics revealed that organic matter negatively affected the uptake of DDT, dieldrin, and heptachlor. Silt negatively affected endrin uptake. Soil moisture content at 0.33 bar tension negatively affected DDT and dieldrin uptake by alfalfa. No significant correlations were found between uptake and soil pH, cation exchange capacity, or clay content.
Soil analysis, 14 or 20 months after insecticide application, revealed residues of the insecticides, in increasing order of persistence, to be heptachlor < dieldrin ≈ endrin < DDT. Correlations calculated between residues in soils and the soil characteristics above, revealed that persistence was positively correlated with soil organic matter.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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