不同草带对坡耕地土壤侵蚀的影响

Effect of Grass Strips on Soil Erosion in Sloping Field

于20012002年进行了“不同草带对坡耕地土壤侵蚀的影响”研究,试验设高羊茅(A)单作、高羊茅与红三叶混作(B)、非洲狗尾草与红三叶混作(C)和一个无草带种植(对照D)4个处理,坡地在13.2°14°。在每个处理上部等高种植玉米,基部种0.5 m宽的草带,底部设径流收集池,主要收集510月玉米生长期间的水土流失量。结果表明:①草带可显著减少径流量和侵蚀量,3种草带处理2年的总径流量和总侵蚀量均极显著(P<0.01)小于对照D,其中非洲狗尾草与红三叶混作的水土保持效果最好,高羊茅与红三叶混作次之,高羊茅单作为第三。②试验地水土流失主要发生在68三个月,这3个月的径流量和侵蚀量分别占总量的96.8%,99.9%,特别是6月径流量和侵蚀量分别占总量的63.2%,80.3%,草带在此期间水土保持效果最显著。所以,在坡耕地上结合农作物等高种植多年生草带是一项简单有效的水土保持技术。

“Effect of grass strips on soil erosion in sloping field” was conducted in 2001 and 2002. Four treatments including Festuca arundinacea （A）. Festuca arundinacea × Trifolium pratense （B）. Setaria sphacelata × Trifolium pro.tense （C） and without grass strip （D）,with three replications which had slopes ranging from 13.2°- 14° were investigated. The contour grass strip with width of 0.5 m was placed at the bottom of each plots. Maize of 18 m^2 was placed at the upper plot. Runoff and sediment were collected during maize growing season （May to October）. The two-year results showed that ①Grass strips substantially reduced runoff and sediment, the total runoff and sediment of three grass strips had reached very notable discrepancy comparing with without grass strip（ P 〈0.01 ） on sloping field in the two years. Setaria sphacelata × Trifolium pratense （C） was the best of three grass strips, the effect or water and soil conservation was Setarir sphacelata × Trifolium pratense （C）〉 Festuca arundinacea × Trifolium pratense （B）〉 Festuca arundinacea （A）〉without grass strip （D）. ② Runoff and soil loss mainly occurred in June, July and August in sloping fields of the experiment, the total runoff and soil loss had readed 96.8% and 99.9% in June, July and August in the two years, especially in June the percentage of loss was 63.2% and 80.3%. The effect of water and soil conservation with three grass strips（A,B,C） was very substantial especially in June than other month. So, the grass strips are an effective and ordinary conservation measure, especially when used in conjunction with contour planting crop.