自然生草对渭北旱塬苹果园土壤孔隙和水分入渗的影响

为促进渭北旱塬果园土壤水分入渗，提高土壤蓄水保水能力，促进苹果生产，以果园清耕为对照，探讨不同年限的自然生草(繁缕和牛繁缕群落，自然生草持续12、8和4年)对果园土壤孔隙、土壤保水性能、土壤水分入渗和苹果品质等的影响。结果表明:自然生草对果园0~40 cm土层土壤容重和土壤孔隙度无显著影响，但显著提高了0~40 cm土层土壤含水量、田间持水量和饱和含水量，极显著提高了土壤水分入渗速率，且自然生草持续的年限越长其影响越大。自然生草提高了苹果产量、果实着色面积、果实硬度、果实可溶性固形物含量和固酸比，但对果实单果质量、果形指数和可滴定酸含量无显著影响。综上，自然生草可改善果园土壤通透性，促进土壤水分入渗，提高果实产量和品质，是改善渭北旱塬果园土壤蓄水保水能力的有效措施。

Effects of self-sown grass on soil porosity and soil infiltration in apple orchard in Weibei dry plateau

In order to promote the soil water infiltration, improve the soil water retention capacity, and promote apple production, with clean tillage as control, the effects of self-sown grass of lasted different years(Stellaria media and Malachium aquaticum community, the self-sown grass lasted 12, 8 and 4 years)on soil porosity, soil water retention, soil infiltration, apple quality and others were systematically investigated in Weibei dry plateau. The results showed that: The self-sown grass had no significant effect on soil bulk density and soil porosity of orchard in 0-40 cm soil layer, but the self-sown grass significantly increased soil moisture, soil field moisture capacity and soil saturation moisture, extremely significant increased soil water infiltration rate. The longer the self-sown grass lasted years, the greater the effects were. The self-sown grass increased the fruit yields, fruit red coefficient, fruit firmness, fruit soluble solids content and the ratio of soluble solids to titratable acid, but had no significant effects on single fruit weight, fruit shape index and fruit titratable acid content. To sum up, the self-sown grass improved soil permeability, promoted soil infiltration, and increased fruit yield and quality. Therefore, the self-sown grass can be an effective measure to improve soil water storage and water conservation of orchard in Weibei dry plateau.