长期不同施肥棕壤玉米地的酶活性之时空变化

为揭示长期不同施肥对棕壤玉米地酶活性时空变化的影响，利用31年长期肥料定位试验研究了玉米生育期内3种主要土壤酶活性的时空变化及其与土壤理化性质的关系。结果表明，棕壤上各种酶随玉米生育期推进而有规律地变化。土壤脲酶、转化酶活性高峰出现在玉米拔节期，酸性磷酸酶活性高峰出现在玉米大喇叭口期；玉米收获后，土壤转化酶、脲酶均高于播前或与播前相当，而酸性磷酸酶活性则低于播前。在同样化肥水平上增施有机肥能增加脲酶、转化酶活性，而降低酸性磷酸酶活性；3种酶活性的空间分布规律均遵循随土层深度加深而不断减小的规律，长期培肥对深层土壤酶活性亦有影响。相关分析结果显示，土壤脲酶同转化酶呈极显著正相关（r=0.636**）；脲酶、转化酶同土壤有机碳、pH、含水量、碱解氮、速效磷基本呈极显著正相关；酸性磷酸酶同各因子无显著关系。土壤酶与土壤肥力因素关系密切，可作为衡量土壤肥力的敏感指标。

Temporal and spatial dynamics of enzyme activities under long-term fertilization in a maize growing brown soil

A long-term fertilizer location experiment(31 years) was carried out to study the temporal and spatial dynamics of enzyme activities under long-term fertilization in a maize growing brown soil.Results showed that enzyme activities changed regularly with the growing of maize.The highest urease and invertase activities were observed at jointing stage,while the highest acid phosphatase activity at the huge bellbottom period.Urease and invertase activities were higher after harvest than before sowing,however ac...