长期定位施肥田土壤酶活性的动态变化特征

Dynamic changes of soil enzyme activities in long-term fertilization soil

为探讨长期施肥条件下玉米生育期内土壤酶活性的动态变化及其与土壤肥力的关系,该文对北京褐潮土定位试验田第12年的土壤酶以及土壤养分因子进行了测定和分析。结果表明,土壤过氧化氢酶、磷酸酶在玉米拔节期出现活性高峰,土壤脲酶在玉米拔节期及成熟期出现两个活性高峰,土壤蔗糖酶在整个玉米生育期内活性变化幅度较小。长期施肥能明显提高土壤中蔗糖酶、脲酶、磷酸酶活性,其中有机肥与化肥配施对于增加土壤中蔗糖酶、脲酶、磷酸酶活性尤为显著。长期施肥降低土壤中过氧化氢酶活性,并且以NPK配施有机肥处理的土壤过氧化氢酶活性降低幅度最大。土壤酶之间及其与土壤养分因子之间具有明显相关性,其中蔗糖酶、脲酶及磷酸酶与土壤养分各因子均呈显著或极显著正相关,除碱解氮外,过氧化氢酶与其余各养分因子呈显著或极显著负相关。

The dynamic changes of soil enzyme activities during growth of corn, in particular, the relationship of soil enzyme activities with the contents of soil nutrients were investigated based on a 12-year long-term fertilizer experiment in Fluvo-aquic soil in Changping County, Beijing, China. The results showed that the activities of hydrogen peroxidas and phosphatase peaked at jointing stage. Urease had two peaks of concentrations at jointing stage and mature stage. Invertase activities had a little change during growth of corn. Long-term application of fertilizers could significantly increase the soil phosphatase, urease and invertase activities. The application of NPK fertilizers combined with organic manure was more effective than others to increase soil enzymes activities. Long-term fertilization especially the application of NPK fertilizers combined with organic manure decreased the activity of hydrogen peroxidase in soil. Significant correlation was found among the soil enzymes activities or between the activities of soil enzymes and the contents of soil nutrients. The significant positive correlations were found between the activities of phosphatase, urease and invertase and the contents of organic matter, total N, alkalified N, total P, available P and available K. Hydrogen peroxidase activities were negatively correlated with soil nutrients contents, except for alkalified N.