秸秆覆盖对东北黑土区坡耕地产流产沙及氮磷流失的阻控

为揭示秸秆覆盖对东北黑土区坡耕地产流产沙及氮磷流失的阻控,通过田间试验,探讨秸秆覆盖模式下,玉米生育期对不同坡度试验小区径流、泥沙和氮磷流失的阻控效果。结果表明:随着耕地坡度的增加,地表径流量、土壤及氮磷流失量逐渐增加。玉米种植条件下,地表径流量与降雨量呈正相关,土壤流失量与降雨量不相关。秸秆覆盖模式对土壤流失的阻控效果均为随坡度的降低,阻控率增加,秸秆覆盖对地表径流和土壤流失阻控率均超过90%。土壤中氮素流失以溶解态氮为主,溶解态氮占总氮的60%以上;磷素流失以颗粒态磷为主,颗粒态磷占总磷的80%以上。秸秆覆盖对土壤中总氮、总磷阻控率均超过85%,对于控制水土流失和降低面源污染风险具有积极意义。

Straw Mulch Controls Runoff and Nitrogen and Phosphorus Loss from Slope Farmland in Black Soil Region of Northeast China

Field experiment was conducted in black soil region of Northeast China to reveal the effects of straw mulching on runoff,sediment and nitrogen and phosphorus loss in different slope experimental plots at different growth periods of corn. The results showed that,surface runoff,soil,nitrogen and phosphorus losses were increased with the increased slope. Under the condition of corn planting,rainfall was positively correlated with surface runoff,but not for soil loss. The reduction rate of straw mulching on soil loss increased with the decreasing slopes. The resistance control rate of straw mulching on surface runoff and soil loss both exceed 90%. Dissolved nitrogen was the main contributor in nitrogen loss in soil,which accounted for more than 60% of total nitrogen. The loss of phosphorus was mainly granular phosphorus is the dominant phosphorus form,which accounted for more than 80% of the total phosphorus. Straw mulching had a resistance control rate of more than 85% for total nitrogen and total phosphorus in soil,which was of positive significance for controlling soil erosion and reducing the risk of non-point source pollution.