干旱区保护性耕作对土壤水分的影响研究

Effect of Plough and Conservation Tillage on Soil Moisture in Ecotone Between Agriculture and Animal Raising of North China

为了研究保护性耕作对土壤水分的影响,选择翻耕地和免耕地两种土地耕作类型,分析不同耕作方式下土壤水分的时空变化规律。在保护性耕作实行的两年时间里,测定了土层不同深度土壤水分,结果表明:(1)在作物生长的整个生育期内土壤水分含量有随降雨量周期变化的趋势,无论是何种耕作方式,除生育期降雨外,播前底墒也是土壤供水的重要组成部分;(2)土壤贮水能力免耕地都是大于翻耕地的;0-80cm土壤水分的空间剖面自上而下分为两个层次:表层失水层(0-30cm)和中层贮水层(30-80cm)。(3)用SPSS统计软件进一步对土壤水分与土层深度的关系进行拟合,结果表明土壤水分与土层深度的关系具有极强的相关性,其关系方程为拟和三次抛物线相型。

In the arid areas of ecotone between agriculture and animal husbandry of north China, soil water is crucial to the plant growing and vegetation restoration. The conservation farming should be introduced in this area. In order to evaluate the effect of different tillage types on soil moisture, the research analysed the temporal and spatial variations of soil moisture under plough tillage and no-tillage. The soil moisture within 0-80cm was measured in short term of two years. The results indicated： （1） In general, the changes of soil moisture content corresponded to the amount of precipitation during the growth season. Including the rainfall, the moisture in the soil before sowing was a vital element whatever the tillage type was. （2） The water storage capacity of no-tillage was more than plough tillage. There were two layers of special variations of profile soil moisture within 0-80cm： water loss layer within 0- 30cm and water storage layer within 30-80cm. （3） Using SPSS software to simulate the relationship between soil moisture content and soil depth, the correlation was obvious and the equation type was cubic parabolic curve.