保护性耕作对水土保持的影响
Effects of Conservation Tillage on Soil and Water Conservation
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摘要: 水土流失已成为制约我国农业可持续发展的主要因素,严重降低了土壤生产力。为解决这一问题,自20世纪90年代起,保护性耕作被引入中国,并相继建立了长期保护性耕作试验基地。该文综述了不同保护性耕作措施对水土保持影响的研究结果,通过平均值方法对黄土高原、东北黑土区和北方沙土区的试验数据进行对比,分析免耕秸秆覆盖、深松和传统耕作对土壤含水率、土壤水蚀、土壤风蚀及土壤肥力的影响规律。结果表明,与传统耕作相比,在黄土高原地区,免耕秸秆覆盖和深松的土壤含水量分别提高了13.6%和31.7%,水分利用效率分别提高了2.26和3.82 kg/(hm2·mm)。在东北黑土区,免耕秸秆覆盖和深松的土壤有机质、速效氮和速效磷的含量分别提高了14.8%和7.1%、10.8%和8.4%及10.8%和8.4%,免耕秸秆覆盖和深松的土壤平均径流量分别减少了32.8%和23.5%。在西北沙土区,免耕秸秆覆盖和深松保护性耕作措施能显著降低土壤风蚀速率,当风速为10 m/s时,土壤风蚀速率分别降低了90.2%和85.0%。Abstract: Soil erosion has become a major factor restricting sustainable development of agriculture in China,which seriously reduces soil productivity.Effects of different tillage measures on soil and water conservation was reviewed.By the method of average,experimental data on loess plateau,northeast black soil area and sand in the north area were sorted out.Influence laws of no-tillage straw mulching,deep loosening and traditional tillage on soil moisture content,soil water erosion,wind erosion and soil fertility was analyed.Results showed that compared with traditional tillage,soil moisture content of no-tillage straw mulching and deep loosening increased by 13.6% and 31.7% respectively,water use efficiency increased by 2.26 and 3.82 kg/(hm2·mm)respectively.In the black soil area of northeast China,contents of soil organic matter,available nitrogen and available phosphorus in no-tillage straw mulch and deep loosening increased by 14.8% and 7.1%,10.8% and 8.4%,10.8% and 8.4% respectively.In the sandy soil area of northwest China,no-tillage straw mulching and deep loosening could significantly reduce soil wind erosion rate.When wind speed was 10 m/s,soil wind erosion rate decreased by 90.2% and 85.0% respectively.