为了降低集约化种植制度下华北平原农田硝酸盐的淋失,该研究选择华北平原高产粮区,开展了为期2 a(2006-2008年)的田间试验,试验设计了2个灌溉处理(常规灌溉处理和基于土壤水分实时监控的优化灌溉处理)和2个施氮处理(传统施氮处理和优化施氮处理),利用张力计结合土壤溶液提取器对土体2 m处的水分和硝酸盐通量进行了监测和计算.研究结果显示,在相同施氮条件下,优化灌溉能够有效降低农田水分的渗漏量,渗漏量仅为传统灌溉渗漏量的50%左右.优化施氮能够有效降低2.1 m土体硝态氮含量,在相同灌溉条件下2.1 m土体硝态氮的残留量部在传统施氮的60%以下,而灌溉方式对硝态氮累积的影响不大.优化水氮管理相比传统水氮管理氮素的淋失量下降了60%,淋失率也下降了50%左右,粮食产量略有提高.%The objective of this study was to provide some suggestions on reducing nitrate leaching from cropland under the intensive cropping pattern in North China Plain. The experiment was carried in a typical high yield production area of Huantai county from 2006 to 2008. Two kinds of irrigations and two kinds of fertilizer N managements were designed,including traditional and optimal irrigation treatments, fertilized with Urea and controlled release fertilizer (CRF). Soil water content and nitrate content in soil solution at the depth of 2 m were observed by tensiometer and ceramic suction cup respectively. The amount of nitrate leaching was calculated by Darcy's law. The results showed that under the same fertilization condition, quantity of water drainage was obviously reduced optimal irrigation treatment, which was about 50％ of that in traditional irrigation treatment. Under the same irrigation treatments, the nitrate content at the depth of 2.1 m soil profile was reduced sharply under the CRF treatment. Irrigation patterns had a insignificant effect on the amount of residual nitrate content in soil profile. The amount of residual nitrate was reduced to 60％ of that in the Urea treatment. Compared with the traditional water and N combined management, amounts of nitrate leaching were reduced by 60％, and nitrate leaching ratio was also declined by 50％ for the CRF treatment without decreasing grain yield. Thus,the optimal irrigation and N-fertilizer management is recommended.
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