长期施肥对东北黑土酶活性的影响

在中国科学院海伦农业生态实验站长期定位试验基础上，研究了长期施用化肥和有机肥对黑土0～20 cm和20～40 cm土层土壤脲酶、磷酸酶、过氧化氢酶和转化酶活性及土壤全碳和全氮的影响.结果表明：长期施用化肥和有机肥均不同程度地提高了0～20 cm和20～40 cm土层土壤磷酸酶、脲酶和转化酶活性，特别是化肥和有机肥配合施用显著增加了该3种土壤酶的活性，增幅分别为43.6%～113.2%、25.9%～79.5%、14.7%～134.4%(0～20 cm)和56.1%～127.2%、14.5%～113.8%、16.2%～207.2%(20～40 cm)，长期施用化肥对土壤过氧化氢酶活性影响不大.随着土层深度的增加，土壤磷酸酶、脲酶和转化酶活性均有所降低；长期施用氮肥对土壤脲酶、施用磷肥对土壤磷酸酶有明显的促进作用；长期施肥对土壤全C、全N含量及C/N也有明显影响.

Effects of long-term fertilization on enzyme activities in black soil of Northeast China.

In this paper, black soil samples at the depths of 0-20 cm and 20-40 cm were collected from the Hailun Agricultural Ecology Station of Chinese Academy of Sciences to study the effects of long-term fertilization on their urease, invertase, phosphatase and catalase activities and total C and N contents. The results showed that long-term application of chemical fertilizers and organic manure increased the activities of urease, invertase and phosphatase in 0-20 cm and 20-40 cm soil layers in different degree, and the combined application of them increased the activities of the three enzymes significantly, with an increment of 43.6%-113.2%, 25.9%-79.5% and 14.7%-134.4% in 0-20 cm soil layer and 56.1%-127.2%, 14.5%-113.8% and 16.2%-207.2% in 20-40 cm soil layer, respectively. However, long-term application of chemical fertilizers without organic manure had little effects on catalase activity. The activities of urease, invertase and phosphatase decreased with increasing soil depth. Long-term application of N fertilizer increased urease activity, and P fertilization had obvious positive effect on phosphatase activity. Long-term fertilization also had obvious effects on the soil total C and N contents and C/N ratio.