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达到持续的农作物高产高效的一个综合途径要求实行保护性制度,同时考虑水土质量两个方面。美国学者R.N.Lerch等人在黏土地上,根据精准农业制度的管理方法,研究测定地表水和地下水水质变化;在常规管理的土地上对土壤质量进行评价;利用此评价来支持精准农业制度的建立。从1991~2003年13 a期间,实行玉米-大豆轮作、覆膜耕作、施用化肥和除草剂。研究表明,现有的管理制度对地表径流造成了负面影响。地表径流中的除草剂、营养物质和沉积物主要来源于土壤侵蚀严重地区。地下水中硝态氮的质量浓度随时间变化零相关,地表水中溶解态氮的质量浓度与氮的施入量、施肥时间有关。过去的150~200多年中,土壤流失的空间变化控制着土壤质量、水质和目前所观察到的作物生产力模式。因此,土壤侵蚀的空间变化,或者替代的量度,如黏土层厚度,是建立保护性精准农业的重要的基础。
A comprehensive approach to sustaining crop productivity and efficiency requires a system of protection that takes into account both soil and water quality. The American scholar R.N.Lerch et al. Studied the change of surface and groundwater quality on the clay soil according to the precision agriculture system management method. The soil quality was evaluated on the conventionally managed land. The evaluation was used to support the establishment of the precision agriculture system. From 1991 to 2003, during the 13-year period, corn-soybean rotation, plastic film mulching, fertilizers and herbicides were applied. Research shows that the existing management system has had a negative impact on surface runoff. Herbicides, nutrients and sediments in surface runoff come mainly from areas with severe soil erosion. The concentration of nitrate nitrogen in groundwater is zero-correlated with time, and the concentration of dissolved nitrogen in surface water is related to the amount of nitrogen applied and fertilization time. Over the past 150-200 years, spatial changes in soil erosion control soil quality, water quality and the crop productivity patterns observed so far. Therefore, spatial changes in soil erosion, or alternative measures such as clay thickness, are important foundations for building conservation precision agriculture.