中文摘要：

【目的】研究连续多年秸秆还田对土壤钾素形态及空间分布（层化现象）的影响。【方法】以关中平原冬小麦-夏玉米轮作体系中连续13年秸秆还田粮田土壤为对象,并以临近葡萄园土壤为对照。比较2种土壤不同土层（0～5,5～15,15～30cm）速效钾及其3种组分（水溶性钾、非特殊吸附钾、特殊吸附钾）、非交换性钾、矿物钾、全钾含量的变化,并分析了土壤中各形态钾的层化比率和相关性。【结果】经过13年秸秆还田,粮田土壤0～5cm土层速效钾及其各组分平均含量均有提高;在5～15和15～30cm土层中,与葡萄园土壤相比,粮田土壤速效钾及其各组分平均含量均降低。粮田土壤速效钾及其各组分的层化比率总体高于葡萄园土壤。与葡萄园土壤相比,粮田土壤非交换性钾含量明显降低。粮田土壤与葡萄园土壤矿物钾和全钾含量差异不大。粮田土壤速效钾与其各组分、非交换性钾、全钾相关性达显著或极显著水平,但与矿物钾相关性不显著;葡萄园土壤速效钾与其各组分和非交换性钾相关性达极显著水平,但与矿物钾、全钾相关性不显著。【结论】整体看,秸秆还田在维持土壤钾有效成分与全钾之间的显著相关关系和协调土壤各形态钾的含量及空间分布方面,均有一定的积极作用。但无论是秸秆还田还是施用化学钾肥,对粮田和葡萄园土壤矿物钾及全钾含量和空间分布的影响均不显著。

英文摘要：

【Objective】This study evaluated the effect of long-term straw returning on form and spatial distribution（stratification）of potassium in agricultural soil.【Method】Soil samples were collected from soil in winter wheat-summer maize rotation field with 13-year straw returning in Guanzhong Plain,and vineyard soil nearby was used as control.Changes in readily available K and its three components（water soluble K,non-specifically adsorptive K,and specifically adsorptive K）,non-exchangeable K,mineral K and total K in different layers（0-5,5-15,and 15-30cm）were investigated and stratification ratio and correlation between different K forms were analyzed.【Results】All components of soil readily available K were significantly increased in 0-5cm soil layer in the grain field soil after 13-years straw returning.However,readily available K contents at 5-15 and 15-30 cm soil layers were lower than that of vineyard soil.Stratification ratios of readily available K and its components in grain field soil were higher than in vineyard soil.Compared with vineyard soil,the content of non-exchangeable K in grain field soil decreased.The con-tents of mineral K and total K were similar in grain field soil and vineyard soil.Readily available K had significant or extremely significant correlation with its components,non exchangeable K and total K,but had no significant correlation with mineral K in grain field soil.Readily available K in vineyard soil had extremely significant correlation with its components and non-exchangeable K,but no significant correlation with mineral K and total K.【Conclusion】Straw returning was preferable to maintain the significant correlation between components with total available K in soil and coordinate the contents and spatial distribution of soil K in different forms.But it had no significant effect on the content and spatial distribution of soil mineral K and total K.