G P Bindumol, C C Harilal
Environmental Science Division, Department of Botany, University of Calicut, Thenhipalam, Kerala, 673 635, India.
Analytical laboratory, Ground water Department, Kozhikode, Kerala, 673 020, India.
Environ Monit Assess. 2017 Sep 15;189(10):506. doi: 10.1007/s10661-017-6142-9.
Leaching potential of pesticides, apart from climatological factors, depends on soil physical properties, soil-pesticide interaction and chemical nature of the molecule. Recent investigations have revealed the presence of various organophosphate pesticides in various agroecosystems. The present study investigated the soil transport mechanism of commonly used organophosphate pesticides in acidic sandy clay loam soils of Kerala State, India. Packed soil column experiment was undertaken under laboratory condition for 30 days. Unsaturated flow was carried out using distilled water/0.01 M CaCl solution after applying chlorpyriphos and quinalphos at the rate of 0.04% a.i.ha and 0.025% a.i.ha, respectively. The study revealed the retention of residues of chlorpyriphos and quinalphos in the top 5-cm layer. Irrespective of the applied concentration of chlorpyriphos and quinalphos, the relative concentration of the pesticides in soil was similar. About 56% of the applied chemicals were dissipated in 30 days of unsaturated flow. A new dissipation compound iron, tricarbonyl [N-(phenyl-2-pyridinylmethyene) benzenamine-N, N'], was detected in GCMS analysis of soil extract from distilled water percolated soil. The dissipation of chlorpyriphos and quinalphos was faster in 0.01 M CaCl-treated soil column. Among the pesticides analysed, the residue of quinalphos was detected in leachate.
除气候因素外，农药的淋溶潜力取决于土壤物理性质、土壤与农药的相互作用以及分子的化学性质。最近的调查发现各种农业生态系统中存在多种有机磷农药。本研究调查了印度喀拉拉邦酸性砂质粘壤土中常用有机磷农药的土壤迁移机制。在实验室条件下进行了30天的填充土柱实验。分别以0.04%有效成分/公顷和0.025%有效成分/公顷的用量施用毒死蜱和喹硫磷后，用蒸馏水/0.01M氯化钙溶液进行非饱和流实验。研究表明，毒死蜱和喹硫磷的残留集中在顶部5厘米土层。无论毒死蜱和喹硫磷的施用浓度如何，土壤中农药的相对浓度相似。在30天的非饱和流实验中，约56%的施用化学品被消散。在蒸馏水渗透土壤的提取物的气相色谱-质谱分析中检测到一种新的消散化合物三羰基铁[N-(苯基-2-吡啶基亚甲基)苯甲胺-N,N']。在0.01M氯化钙处理的土柱中，毒死蜱和喹硫磷的消散速度更快。在所分析的农药中，在渗滤液中检测到了喹硫磷的残留。
