翻耕和覆盖对坡耕地产流产沙的影响

Effect of tilling and mulching on runoff yield and sediment yield in slope farmland

为了研究减小坡耕地水土流失的方法,本试验在人工降雨条件下,研究坡度、土壤容重和秸秆覆盖3种因素对产流和产沙的影响。试验结果表明:3个因素中坡度对产沙量影响最大,15°坡以内,随着坡度增大,总产流量增大,总产沙量迅速增大。翻耕可以有效增加降雨入渗,但总产沙量随着容重的减小而增大。小于10°的坡耕地翻耕至容重1.2g·cm^(-3)时保水效果明显而产沙量增加不大。增加秸秆覆盖可以有效减小总产流量和总产沙量,且坡度越大减沙效果越明显。坡耕地尽量选择缓坡地;小于10°坡耕地翻耕至容重1.2g·cm^(-3)为宜,大于10°坡耕地免耕;在秸秆覆盖率不超过80%的前提下尽量增加秸秆覆盖。

A field rainfall simulation experiment was carried out to seek a way of reducing soil and water loss in sloped lands.The effects of slope,soil bulk density and residue cover on runoff yield and sediment yield were also studied.The results showed that the effect of slope on sediment yield was greatest in the 3factors.Runoff yield and Sediment yield increased with slope increasing within 15°.The rainfall infiltration could be effectively increased,but the total sediment yield increased with the decrease of bulk density.When soil bulk density was 1.2g·cm（-3）,runoff reduced markedly with a little sediment yield increase.Residue cover could effectively decrease runoff yield and sediment yield,and the effect of sediment yield was more significant.Slope should choose small slope.Soil bulk density should choose1.2g·cm（-3）when slope less than 10°.Slope land should choose no-tillage when slope more than 10°.We should increase the straw mulching.But the straw mulching rate should not exceed 80%.