节水灌溉条件下有机磷农药在设施蔬菜土壤中迁移及机制研究

In recent years, the areas of Greenhouse in China are increasing year by year. Compared with that in open field, much more pesticides are used in Greenhouse. Overmuch input of pesticides is treatening the safty of the soil and underground water. The problem is huge and growing. Irrigation is one of most important rural activities in Greenhouse. The physicochemical properties were changed by irrigation, which results in the change on pesticide migration in the soil under Greenhouse. The project intends to study the transport and mechanism of organophosphorus pesticides in soil under Greenhouse. Soil column tests will be used. Hot pepper is widely cultivated in Greenhouse,so it will be used as the crop in this research. Two types of soil will be filled in the column. Chlorpyrifos and Omethoate will be used as the object of the study ,because they are widely used in china and have different physicochemical characteristics. The impact of details of the irrigation system (irrigation volume, irrigation amount, irrigation period and the irrigation frequency) under different irrigation methods(focusing on water-saving irrigation method) on organophosphorus pesticides migration in the soil under Greenhouse will be investigated. The research will provide a reference for the safety evaluation of the pesticide contamination in soil and groundwater below the Greenhouse

近年来设施温室在我国发展迅速，与露地栽培相比，温室设施内土壤农药污染更加严重，给温室地区地下水安全带来威胁。灌溉是温室中重要的农业活动之一，灌溉改变了土壤理化性质，必然改变农药在土壤中的迁移和转化，研究灌溉对农药在温室土壤中迁移的影响具有重要意义。本课题拟采用温室中广泛种植的辣椒作为供试作物，选取不同质地土壤，以两种使用广泛且性质差别较大的有机磷农药毒死蜱和氧化乐果为研究对象，研究不同灌溉方式（滴灌、微喷灌和漫灌）、不同灌溉制度（灌溉量、次灌水量、灌水频率）下，农药在设施蔬菜土壤中的迁移及机制，重点探索节水灌溉条件下有机磷农药的迁移及主要影响因素。研究成果将为温室种植地区地下水及土壤农药污染安全性评价提供一定参考依据

近年来设施温室在我国发展迅速，与露地栽培相比，温室设施内土壤农药污染更加严重，给温室地区地下水安全带来威胁。灌溉是温室中重要的农业活动之一，灌溉改变了土壤理化性质，必然改变农药在土壤中的迁移和转化，研究灌溉对农药在温室土壤中迁移的影响具有重要意义。本课题采用温室中广泛种植的辣椒作为供试作物，以有机磷农药毒死蜱和氧化乐果为研究对象，以漫灌为对照，通过土柱模拟试验，研究滴灌方式下有机磷农药在设施蔬菜土壤中迁移和转化；通过土盆试验，以毒死蜱为研究对象，研究灌溉方式对毒死蜱降解及土壤酶活性和微生物量炭、氮的影响。.土柱淋溶实验结果表明：灌溉方式对农药在土壤中迁移有很大影响，滴灌条件下，农药更容易富集在土壤中，而漫灌条件下，农药更容易向下迁移，从而污染地下水；灌水量越大，农药向下迁移距离越大；水溶性农药更容易随水迁移，对地下水造成威胁；土壤消毒处理抑制了毒死蜱在土壤中的降解；作物存在有利于毒死蜱的降解；未消毒、消毒和种植作物处理下，土壤酶活性有较大差异；毒死蜱导致对微生物炭量减少，作物存在下毒死蜱对微生物炭量的影响不明显。.土盆降解实验表明：含水率影响毒死蜱在土壤中的降解，毒死蜱在70%含水率的降解速度最快；含水率影响土壤酶活性，不同毒死蜱浓度，含水率对土壤酶活性的影响不同；灌溉方式对毒死蜱在土壤中降解无显著影响，高浓度毒死蜱降解半衰期增长，土壤消毒抑制了毒死蜱的降解；不同消毒方式下，施加毒死蜱对土壤酶活性与未消毒条件下不同。