Increasing use of herbicides in modern agriculture poses potential risks of crop phytotoxicity, contamination of land and water resources, and adverse impacts on human and ecosystem health. Apart from climatic conditions and soil properties, agronomic practices can significantly influence the persistence of herbicides in soil. Therefore, we assessed the impact of 13-year conservation agriculture (CA) on soil properties as well as on the fate (persistence and leaching) of pendimethalin herbicide in an alluvial sandy loam soil (Typic Haplustept) in comparison with an intensively tillage-based conventional system. The experiment involved two cropping systems (mungbean (Vigna radiata L.)–wheat (Triticum aestivum L.) and sorghum (Sorghum bicolor L.)–wheat as summer and winter crops respectively) and three tillage practices: zero tillage with crop residue retention in both summer and winter seasons (ZT-ZT), conventional tillage in summer and zero tillage with residue retention in winter (CT-ZT) and conventional tillage in both seasons (CT-CT). The adoption of ZT-ZT system resulted in a 24% increase in infiltration rate, 13% greater moisture retention and 69% higher organic carbon content in surface (0–0.05 m) soil over CT-CT. In contrast, under the CT-ZT treatment, only a small change in the above soil properties was observed, which indicated that the benefits associated with CA were negated as soon as the soil was tilled in the subsequent season. In terms of herbicide leaching, under ZT-ZT, a greater fraction (4.1% vs 2.6%) of pendimethalin residues percolated down into the subsurface soil (0.15–0.30 m) than under the CT-CT system, most likely due to greater pore connectivity with the zero-till situation. However, there was a non-significant difference in the overall dissipation of the herbicide from the surface soil (0–0.05 m) under different systems. The field study illustrated that long-term adoption of CA under mungbean–wheat and sorghum–wheat cropping systems can lead to a significant change in soil properties and these in turn can influence the fate of herbicides in soils.

中文翻译：

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长期保护性农业引起的土壤性质变化对不同种植制度下二甲戊灵持久性的影响

在现代农业中越来越多地使用除草剂会带来作物植物毒性、土地和水资源污染以及对人类和生态系统健康的不利影响的潜在风险。除了气候条件和土壤特性之外，农艺实践也会显着影响除草剂在土壤中的持久性。因此，我们评估了 13 年保护性农业 (CA) 对冲积砂壤土 (Typic Haplustept) 中的土壤特性以及对二甲戊灵除草剂的归宿（持久性和浸出）的影响，与基于集约耕作的常规系统。该实验涉及两种种植系统（绿豆（Vigna radiata L.）-小麦（Triticum aestivum L.）和高粱（Sorghum bicolor L.）-分别作为夏季和冬季作物的小麦）和三种耕作方式：夏冬两季零耕（ZT-ZT）、夏季常规耕作和冬季零耕（CT-ZT）和两季常规耕作（CT-CT）。与 CT-CT 相比，ZT-ZT 系统的采用使表层（0-0.05 m）土壤的入渗率提高了 24%，保水率提高了 13%，有机碳含量提高了 69%。相比之下，在 CT-ZT 处理下，仅观察到上述土壤性质的微小变化，这表明随着土壤在随后的季节耕种，与 CA 相关的收益就被抵消了。在除草剂浸出方面，在 ZT-ZT 下，与 CT-CT 系统下相比，更多比例（4.1% 对 2.6%）的二甲戊灵残留物渗入地下土壤（0.15-0.30 m），最有可能是由于在零耕作情况下更大的孔隙连通性。然而，在不同系统下，除草剂从表层土壤（0-0.05 m）的整体消散没有显着差异。田间研究表明，在绿豆-小麦和高粱-小麦种植系统下长期采用 CA 可导致土壤性质发生显着变化，进而影响土壤中除草剂的归宿。