半干旱区不同起垄方式对苜蓿地土壤质量的影响评价

利用多元统计方法综合评价半干旱区不同起垄方式对苜蓿地土壤质量影响的结果表明，传统平作，垄面覆膜的宽、窄垄处理，裸露的宽、窄垄沟处理的土壤质量综合指标值分别为0．261、0．737、0．608、0．342和0．335。说明垄上覆膜宽垄处理的土壤质量最好，其次是垄上覆膜窄垄处理和两含裸露处理，土壤质量最差的是传统平作。这与生产力结果不完全相同，说明单纯追求生产力会给土壤质量带来不利影响。垄上覆膜宽垄是黄土高原半干旱区人工苗蓿地建设的理想模式，它不仅产量高而且相比之下土壤质量也最高。

Impact Evaluation of Different Ridge-forming Pattern on Soil Quality of Alfalfa in the Semi-arid Loess Plateau

Multivariate statistical method was involved to evaluate the impact of different ridge-forming pattern on soil quality of alfalfa in the semi-arid Loess Plateau.Five treatments were designed in this study: conventional cultivation in a flat plot without mulch,plastic mulched ridge with both ridge and furrow 30 cm wide,plastic-mulched ridge with both ridge and furrow 60 cm wide,bare ridge with both ridge and furrow 30 cm wide,and bare ridge with both ridge and furrow 60 cm wide,the values of soil quality integrated(ISQI) of five treatments were 0.261,0.737,0.608,0.342 and 0.335,respectively.The results showed that plastic-mulched ridge with both wide ridge and furrow with the best soil quality of the five treatments was followed by plastic-mulched ridge with both Narrow ridge and furrow and the two un-mulched treatments.The soil quality of check was the worst one in the study.The trend of soil quality in the study was not exactly same with that of productivity.Therefore,the intensive pursuit for high productivity of alfalfa will bring about negative impact on soil quality.In Semi-arid Loess Plateau area,agricultural production should be weighed against the consumption of soil nutrients to achieve the sustainable land use.The results showed also that plastic-mulched ridge with both wide ridge and furrow was the ideal model for establishing alfalfa in the Semi-arid Loess Plateau,which not only had higher hay yield but also higher soil quality.