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以渭北黄土区农林实践中被广泛采用的核桃-小麦间作复合模式为研究对象,以两物种的单作系统为对照,研究单作农田向农林复合系统转变对土壤物理性质的影响,为农林复合系统经营管理和模型的建立提供理论依据.结果表明:核桃-小麦间作对土壤物理性质的改善作用主要发生在0~40 cm土层.核桃-小麦间作可以避免表层(0~20 cm)土壤容重升高,同时在20~40 cm土层对单作农田形成的犁底层也有显著的改善作用.核桃-小麦间作对各土层田间持水量均表现出持续的改善作用,除在20~40 cm土层略低于核桃单作外,其他从第5年开始均高于两单作系统.核桃-小麦间作对各土层土壤孔隙度均存在持续的改善作用,在0~20和20~40 cm土层与两单作系统相比存在显著差异,同时也能提高毛管空隙度的比例.农田向农林复合系统转变过程中对土壤容重、田间持水量、土壤孔隙度均有持续的改善作用,且对浅层土壤的改善作用强于深层土壤.
Taking the walnut-wheat intercropping pattern widely used in agriculture and forestry practice in Weibei Loess Plateau as the research object, the single-cropping system of two species was taken as a control to study the impact of single cropping system on agroforestry system on soil physical properties, The results showed that the improvement effect of walnut-wheat intercropping on soil physical properties mainly occurred in 0-40 cm soil layer.The walnut-wheat intercropping could avoid the surface soil (0-20 cm) soil The results also showed that the soil bulk density increased at 20 ~ 40 cm soil layer, while the plow bottom layer formed in monoculture farmland also improved significantly in the 20-40 cm soil layer. cm soil layer was slightly lower than that of single walnut and the others were higher than those of single cropping system from the fifth year.The walnut-wheat intercropping had a continuous improvement on the soil porosity of all soil layers, and at 0 ~ 20 and 20 ~ 40 cm soil layer was significantly different from that of two single cropping systems and the ratio of capillary porosity was also increased.The soil bulk density, field water holding capacity and soil porosity were continuously improved in farmland conversion to agroforestry system Role, and the improvement of shallow soil stronger than deep soil.