合肥近郊旱地土壤养分径流流失途径的研究

Runoff loss ways of nutrients in non-irrigated farmland in Hefei outskirts.

以合肥近郊旱作平地为实验观测区 ,选择土壤类型为黄褐土 ,地面坡度在 3°以内 ,粮、油、棉、菜等不同作物组合和不同覆盖率的旱作耕地 ,对不同降雨强度下径流产生的时间、径流量及其中携带泥沙量进行长期实地观测和连续 3年采样 (水样和土样 )分析 ,初步查明合肥近郊旱作平地表土和养分的流失与山地和坡地的流失行为显然不同 ,N、P、K有效养分流失量 98%以上是通过“化学侵蚀”流失的 ;“物理侵蚀”是表土和土壤有机质流失的主要途径 (占有机质流失总量的 96 .14 % ) .

Taking non irrigated flatlands in Hefei outskirts as experiment observation areas, yellow brown soil as selected soil type, and < 3°as ground slope,the time of runoff development,runoff quantities,and silt carrying capacity under different rainfall intensity were observed on the non irrigated farmlands with different kinds of crops such as grain, oil, cotton and vegetables,and with different coverage for continuous 3 years.Based on the observation, water and soil samples were collected and analyzed.The results showed that the loss way of the surface soil and nutrients in non irrigated flatlands was obviously different from that on the sloping fields and on the upland.Over 98% of available N, P, and K nutrient loss were run off by chemical erosion.Physical erosion was the main way of the surface soil and organic matter loss, and 96.14% of total organic loss was caused by physical erosion.