豫西南山区不同用地类型土壤养分流失特征

目的]对豫西南山区不同用地类型养分流失特征进行研究,为区域土地规划、水土流失和农业面源污染的防控提供科学依据。方法]选取桃庄河流域和铁瓦河流域5类常见农田,监测其地表径流中的养分浓度,并用SCS模型估算了平水年份农田中随地表径流流失的养分数量。结果]各种农田径流中的养分含量和平水年随径流流失的养分数量基本一致,桃庄河流域表现为:COD_(Mn)氮肥磷肥;铁瓦河流域是:氮肥COD_(Mn)磷肥,这表明前者施用的有机肥和氮肥较多,后者则是氮肥和有机肥较多;不同农田随径流流失的养分数量状况,桃庄河流域为:药材地芝麻地玉米地花生地果园;铁瓦河流域则为:蔬菜地玉米地坡地林地果园,这不仅与施肥种类及数量有关,还与种植的作物、下垫面等状况有关。结论]该区需调整作物结构、改变盲目施肥的传统,减少养分流失和面源污染。

Features of Soil Nutrients Loss Under Different Land Use in Southwest Mountainous Areas of He'nan Province

Objective] The nutrient loss characteristics in different land use types were studied in southwest mountainous areas of He''nan Province to provide scientific basis for regional land planning, and for the prevention and control of agricultural non-point source pollution, water loss and soil erosion. Methods] Five kinds of common farmland were selected in Taozhuanghe basin and Tiewahe basin, and wherein the nutrients concentrations in runoff were monitored and the nutrients loss was estimated by SCS model in normal flow year from different fields. Results] The nutrients contents in all kinds of farmland were coincided with their loss observed in normal flow year, but were different in different catchment. In Taozhuanghe basin, COD was the most, nitrogen fertilizer was moderate and phosphate fertilizer was the least; while in Tiewahe basin, nitrogen fertilizer was the most, COD was moderate and phosphate fertilizer was the least. This indicated organic and nitrogen fertilizer were more preferably used in Taozhuanghe basin; nitrogen and ^*organic fertilizer were more frequently used in Tiewahe basin. Nutrients loss varied in different fields, in Taozhuanghe basin the rank was: herbs > sesame > corn > peanut > orchard; In Tiewahe basin, it was: vegetable > corn > slope > woodland > orchard. Nutrients loss was not only related to fertilizer type and application quantity, but also to the condition of underlying surface, such as slope, crops, etc. Conclusion] It is necessary that the crop structure should be adjusted and the traditional fertilization custom should be changed according to local conditions to reduce nutrient loss and non-point source pollution.