条带休闲轮种对坡地水土流失和水分利用效率的影响

Effects of strip planting and fallow rotation on the soil and water loss and water use efficiency of slope farmland

为提高宁南旱区坡耕地土壤保水能力、减少水土流失,于2007—2010年在10°～15°坡耕地上,以传统无条带种植模式为对照,研究条带隔年休闲轮种模式对农田土壤水分动态、水土流失特征和水分利用效率的影响.结果表明:经过4年休闲轮种,条带处理比传统无条带种植处理显著增加0～200cm土层土壤含水量4.9%～7.0%;条带轮种比无条带模式有效保蓄雨季休闲期降水,明显改善了作物生育前期的土壤水分状况,条带处理0～200cm土层土壤含水量比对照显著增加5.4%～8.5%.与对照相比,条带休闲轮种处理地表径流减少0.7～3.2m3.hm-2,泥沙量减少0.2～1.9t.hm-2,土壤全N损失量减少42.1%～73.3%,作物水分利用效率提高6.1%～24.9%,降水利用效率提高6.3%～15.3%.

In order to enhance the soil water-retaining capacity of slope farmland and reduce its soil and water loss,a field study was conducted in 2007-2010 to examine the effects of strip planting and fallow rotation on the soil water regime,soil and water loss characteristics,and water use efficiency of a 10°-15° slope farmland in the arid area of southern Ningxia,Northwest China.Compared with the traditional no-strip planting,strip planting and fallow rotation increased the soil water content in 0-200 cm layer significantly,with an increment of 4.9%-7.0%.Strip planting and fallow rotation pattern could also effectively conserve the soil water in rain season,and obviously improve the soil water regime at crops early growth stages.As compared to no-strip planting,strip planting and fallow rotation increased the soil water content in 0-200 cm layer by 5.4%-8.5%,decreased the surface runoff by 0.7-3.2 m3·hm-2,sediment runoff by 0.2-1.9 t·hm-2,and soil total N loss by 42.1%-73.3%,while improved the crop water use efficiency by 6.1%-24.9% and the precipitation use efficiency by 6.3%-15.3%.