Dissipation and leaching of (14)C-monocrotophos in Soil Columns under subtropical climate.
Dissipation and leaching behavior of 14C-monocrotophos was studied for 365 days under field conditions using PVC cylinders. The first set (24 cylinders) was spiked with 1.0 microCi 14C-labeled monocrotophos along with 1.06 mg unlabeled monocrotophos to give a concentration of 2 mg kg -1 in the soil up to 15 cm depth. The second set (24 cylinders) received 14C-labeled monocrotophos along with other non-labeled insecticides viz., dimethoate @ 300 g a.i ha-1, deltamethrin @ 12.5 g a.i ha-1, endosulfan @ 750 g a.i ha-1, cypermethrin @ 60 g a.i ha-1, and triazophos @ 600 g a.i ha-1 at an interval of 15 days each as recommended for the cotton crop. 14C-monocrotophos dissipated faster, up to 45% in first 90 days in columns treated with only monocrotophos compared to 25% in columns that received monocrotophos along with other insecticides. However, both the columns showed similar residues 180 days onward. After 180 days of treatment, 46% radiolabeled residues were observed, which reduced up to 39.6% after 365 days. Leaching of 14C-monocrotophos to 15-30 cm soil layer was observed in both the experimental setups. In the 15-30 cm soil layer of both soil columns, up to 0.19 mg 14C-monocrotophos kg-1d. wt. soil was detected after 270 days.
Vig
Komal
K
Department of Zoology, University of Delhi, Delhi, India. kvig@zoology.du.ac.in
Singh
D K
DK
Agarwal
H C
HC
D000327:Adsorption; D002250:Carbon Radioisotopes; D004784:Environmental Monitoring; D003368:Gossypium / Q000737:chemistry; D007306:Insecticides / Q000032:analysis* / Q000737:chemistry; D008999:Monocrotophos / Q000032:analysis* / Q000737:chemistry; D010573:Pesticide Residues / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D013997:Time Factors; D014329:Tropical Climate
D002250:Carbon Radioisotopes; D007306:Insecticides; D010573:Pesticide Residues; D012989:Soil Pollutants; D008999:Monocrotophos