轮耕对冬小麦田土壤酶活性时空变化的影响

为了解轮耕对土壤酶活性的影响,采用田间定位试验,比较和分析了秸秆还田和不还田条件下,连续3年常规耕作(3C)、1年深翻+2年常规耕作(DP2C)、2年深翻+1年常规耕作(2DPC)和连续3年深翻(3DP)处理的冬小麦田土壤酶活性时空变化特点。结果表明,秸秆还田和深翻均可提高0~40cm土层土壤蔗糖酶、脲酶、碱性磷酸酶和过氧化氢酶的活性,其中秸秆还田后平均增幅分别为24.92%、9.20%、6.66%和11.04%,经深翻处理后平均增幅分别为5.33%、6.26%、2.02%和3.43%。随着土层深度增加,各处理土壤酶活性逐渐降低,2DPC和3DP处理相对3C处理20~40cm土层4种土壤酶活性降低幅度较小。秸秆还田配合2DPC、3DP土壤耕作处理不仅能提高酶活性,也有利于酶在土壤中均匀分布。

Effects of Rotational Tillage on Spatial and Temporal Variation of Soil Enzyme Activities in Winter Wheat Field

In order to study the effects of rotational tillage on soil enzyme activities in winter wheat field, experiment was conducted in Luoyang city, Henan province from 2009 to 2012. Eight treatments were arranged in a split plot design. The whole plot treatment factors were S (wheat and maize straw retention) and NS (no straw retention).The subplot treatment factors were the tillage modes, including 3C (shallow ploughing for three years) , DP2C (deep ploughing for the fist year and shallow ploughing for following two years), 2DPC (deep ploughing for two years and shallow ploughing for the third year) and 3DP (deep ploughing for constant three years). The activities of invertase, urease, alkaline phosphatase and catalase within 0~40 cm soil layer were investigated for different treatments during winter wheat growing season. The results showed that, compared with NS, the activities of invertase, urease, alkaline phosphatase and catalase were significantly increased by 24.92%, 9.2%, 6.66% and 11.04% on average in the 0~40 cm layer of S treatment, respectively. In addition, after long time shallow tillage, the activities of these soil enzymes under deep ploughing were higher than those under 3C in 0~40 cm layer, being 5.33%, 6.26%, 2.02% and 3.43% on average,respectively. Under the same condition of straw retention treatments, the activities of all soil enzymes in 0~40 cm layer of 2DPC and 3DP were higher than that of 3C. The activities of those enzymes decreased with settlement depth, but the activities of those soil enzymes of 2DPC and 3DP were significantly higher than the other treatments. It indicated that the treatments of 2DPC and 3DP under straw retention were contributed to improve the activities of soil enzymes and their even distribution in field.