渭北黄土高原旱地果园生草对土壤物理性质的影响

 【目的】研究旱地果园生草土壤物理性状的变化特征。【方法】在黄土高原旱地苹果园生草区及清耕区设立标准地，在60 cm土层内分层取样，测定土壤容重、孔隙度、水稳性团聚体的含量等土壤物理性状，分析果园生草土壤物理性质的变化特征。【结果】生草降低土壤容重，增加孔隙度，提高水稳性团聚体含量，其影响主要集中在0～40 cm土层；生草种类不同，对果园土壤物理性状影响存在差异，种植白三叶效果更佳；随着生草年限的增加，果园土壤物理性状愈趋改善，土壤的入渗性能和持水能力得到较大幅度的提高。【结论】长期生草有利于果园土壤物理性状的持续改善。

Effects of Different Herbage on Soil Quality Characteristics of Non-Irrigated Apple Orchard in Weibei Loess Plateau

The plots were layout in planting herbage areas and till areas of different herbage in non-irrigated apple orchard from the Weibei Loess Plateau, soil samples from different soil layers within 60 cm in every plot were collected. By analyzing soil samples, effects of different herbage on soil physical properties of the apple orchard were studied. The results showed that soil bulk density was reduced, soil porosity was increased and the content of water-stable aggregates was increased after different herbage was planted. The changes in soil physical properties with growing different herbage in non-irrigated apple orchard were mainly in 40 cm soil layer. The change feature of soil physical properties was different in various growing herbage land. With growing herbage years, soil physical properties of growing herbage land were improved better. Soil water content and soil water-holding capacity were enhanced greatly. Consequently, growing herbage in orchard in long term can improve the soil properties of orchard lastly, white clover was better than perennial ryegrass in improving soil physical properties.