寒地黑土大豆轮作与连作不同年限土壤酶活性及相关肥力因子的变化

以中国科学院海伦农业生态实验站长期定位试验为平台,研究了寒地黑土大豆轮作与连作不同年限土壤酶活性与相关肥力因子的变化及其相关性和土壤C、N和C/N的变化.结果表明:大豆轮作与连作不同年限,土壤酶活性、有效养分(碱解氮、速效磷和速效钾)含量和土壤C、N及C/N均有较大变化,与正茬相比,迎茬、连作土壤酶活性均降低,其中连作二年,脲酶、转化酶和磷酸酶活性降低幅度最大,分别比正茬降低了29.6%、51.0%和41.9%;土壤C、N和碱解氮、速效磷及速效钾也是大豆连作二年降低最多,分别比正茬降低了18.0%、35.3%和40.4%、53.6%、41.3%,随着连作年限的延长,土壤C、N及有效养分含量均有所恢复,但大豆长期连作,上述各种成分又呈下降趋势.土壤酶活性与土壤C、碱解氮、速效磷、速效钾之间均存在一定的相关性,其中,脲酶、转化酶、磷酸酶与各种养分间均呈极显著正相关.因此大豆连作使土壤酶活性降低,有效养分含量下降,是造成大豆连作障碍而导致大豆减产的重要原因之一.

Variation of Soil Enzymes Activity and Relevant Nutrients at Different Years of Soybean(Glycine max L.)Rotation,Alternate and Continuous Cropping

In this paper,soil samples were collected from soybean rotation and continuous cropping fields for different years in the Hailun Agricultural Ecology Station of Chinese Academy of Sciences to study the variation of soil enzymes activity,nutrients,soil C and N contents and their relationship.The results showed that there was a great variation of soil enzymes activity,available nutrients and soil C and N contents,compared with soybean rotation,soil enzymes activity all decreased in alternate and continuous cr...