title: Effect of soil wetting and drying cycles on metolachlor fate in soil applied as a commercial or controlled-release formulation.
abstract: A controlled-release formulation (CRF) has been developed for metolachlor, which reduced its leaching in a sandy soil and improved weed control in comparison with the commercial formulation. The current study tested the effect of soil wetting and drying cycles (WDCs) on metolachlor fate (desorption, leaching, and weed control) applied as the CRF and as the commercial formulation. Metolachlor adsorption to a heavy soil (Terra-Rosa) was predominately to the clay minerals and oxides. Metolachlor release from a heavy soil subjected to WDCs was higher than its release from the soil not subjected to WDCs. Consequently, a bioassay in soil columns treated with the commercial formulation indicated enhanced metolachlor leaching in heavy soils under WDCs. In contrast, when metolachlor was applied as the CRF, leaching was suppressed and not affected by WDCs. These results emphasize the advantages of the CRF also in heavy soils subjected to WDCs.
authors.affiliation: Department of Soil and Water, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Osnat
authors.initials: O
authors.lastname: Goldreich
authors.forename: Yaakov
authors.initials: Y
authors.lastname: Goldwasser
authors.forename: Yael G
authors.initials: YG
authors.lastname: Mishael
mesh_terms: D000081:Acetamides / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry*; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000737:chemistry; D014867:Water / Q000032:analysis
chemical_list: D000081:Acetamides; D003692:Delayed-Action Preparations; D006540:Herbicides; D012987:Soil; D012989:Soil Pollutants; D014867:Water; C051786:metolachlor