Ma Qingli, Wauchope R Don, Rojas Kenneth W, Ahuja Lajpat R, Ma Liwang, Malone Robert W
Environmental and Turf Services, Inc, Wheaton, MD 20902, USA.
Pest Manag Sci. 2004 Mar;60(3):240-52. doi: 10.1002/ps.790.
The Root Zone Water Quality Model (RZWQM) is a one-dimensional, numerical model for simulating water movement and chemical transport under a variety of management and weather scenarios at the field scale. The pesticide module of RZWQM includes detailed algorithms that describe the complex interactions between pesticides and the environment. We have simulated a range of situations with RZWQM, including foliar interception and washoff of a multiply applied insecticide (chlorpyrifos) to growing corn, and herbicides (alachlor, atrazine, flumetsulam) with pH-dependent soil sorption, to examine whether the model appears to generate reasonable results. The model was also tested using chlorpyrifos and flumetsulam for the sensitivity of its predictions of chemical fate and water and pesticide runoff to various input parameters. The model appears to generate reasonable representations of the fate and partitioning of surface- and foliar-applied chemicals, and the sorption of weakly acidic or basic pesticides, processes that are becoming increasingly important for describing adequately the environmental behavior of newer pesticides. However, the kinetic sorption algorithms for charged pesticides appear to be faulty. Of the 29 parameters and variables analyzed, chlorpyrifos half-life, the Freundlich adsorption exponent, the fraction of kinetic sorption sites, air temperature, soil bulk density, soil-water content at 33 kPa suction head and rainfall were most sensitive for predictions of chlorpyrifos residues in soil. The latter three inputs and the saturated hydraulic conductivity of the soil and surface crusts were most sensitive for predictions of surface water runoff and water-phase loss of chlorpyrifos. In addition, predictions of flumetsulam (a weak acid) runoff and dynamics in soil were sensitive to the Freundlich equilibrium adsorption constant, soil pH and its dissociation coefficient.
根区水质模型（RZWQM）是一个一维数值模型，用于模拟田间尺度下各种管理和气象情景下的水分运动和化学物质迁移。RZWQM的农药模块包含详细算法，描述了农药与环境之间的复杂相互作用。我们利用RZWQM模拟了一系列情况，包括多次施用杀虫剂（毒死蜱）对生长中的玉米的叶面截留和冲刷，以及对土壤吸附与pH值相关的除草剂（甲草胺、莠去津、氟嘧磺隆），以检验该模型是否能得出合理结果。还使用毒死蜱和氟嘧磺隆对该模型进行了测试，以考察其对化学物质归宿以及水和农药径流预测对各种输入参数的敏感性。该模型似乎能合理呈现地表和叶面施用化学物质的归宿和分配情况，以及弱酸性或碱性农药的吸附情况，这些过程对于充分描述新型农药的环境行为变得越来越重要。然而，带电荷农药的动力学吸附算法似乎存在缺陷。在所分析的29个参数和变量中，毒死蜱半衰期、弗伦德利希吸附指数、动力学吸附位点分数、气温、土壤容重、33 kPa吸力水头下的土壤含水量和降雨量对土壤中毒死蜱残留量的预测最为敏感。后三个输入参数以及土壤和地表结皮的饱和导水率对地表径流和毒死蜱水相损失的预测最为敏感。此外，氟嘧磺隆（一种弱酸）径流和土壤动态的预测对弗伦德利希平衡吸附常数、土壤pH值及其解离系数敏感。
