坡耕地种植牧草固土净水综合效应研究

Study on General Effect of Soil and Water Conservation by Planting Pastures in Slope Cultivated Land

在云龙水库水源保护区16.5°坡耕地上,种植豆科、禾本科、菊科多年生牧草,替代传统的种植模式（玉米-小麦）.试验结果表明,种植牧草能有效降低水土及养分流失.种草模式下的径流及土壤流失量分别比习惯种植减少27.6％～35.8％及41.8％ ～54.6％,氮磷钾养分流失减少34.1％～41.3％,其中氮流失减少32.7％～39.4％,磷流失减少33.9％～39.2％.水土保持效果以种植禾本科牧草最好,菊科牧草稍差,豆科牧草居中.同时种植牧草还能取得较好的经济效益,纯收益比习惯种植增加11.0％ ～15.0％,是水源保护区种植结构调整、水源保护及坡耕地综合治理的较好方式.

In Yunlong water conservation areas, the perennial pastures like legume forages, grass forages and composite pastures were planted in the 16.5°slope cultivated land instead of traditional planting mode （corn-wheat）. According to the experiment, planting pastures could efficiently decrease the soil erosion and loss of water and nutrition. Compared to the traditional planting way, during the mode of planting pastures, the runoff flow and loss of soil dropped about 27.6 % - 35.8 % and 41.8 % - 54.6 %, respectively. The loss of nitrogen, phos- phorus and potassium decreased 34.1% - 41.3 %, especially the loss of nitrogen reduced 32.7 % - 39.4 % and the loss of phosphorus reduced 33.9 % - 39.2 %. The grass forages had a great effect on the conservation of water and soil, the legume forages had moderate effect, and the effect of composite pastures was weak. Planting various pastures will lead to a better economic income, and the economic in- terests will increase by 11.0 % - 15.0 %, which is an optimum way to adjust the structure of plantation, preserve water in water source pro. tection area, and control the environmental problems in slope cultivated lands.