秸秆还田对岩溶区与非岩溶区土壤酶活性影响的对比研究

通过室内模拟试验,研究了岩溶区棕色石灰土与非岩溶区红壤对玉米秸秆有机物料降解过程中土壤pH值、秸秆降解率和酶活性的变化特征。结果表明:秸秆降解期间,土壤pH值在前期有下降的趋势,后期慢慢回升;秸秆降解速度最快主要集中在降解最初30 d,之后呈缓慢上升趋势,到98d 基本达到平衡,降解速度大大减慢;过氧化氢酶的变化不明显,土壤蔗糖酶、脲酶、纤维素酶和蛋白酶活性都在不同程度上呈现"前期上升,中期下降,后期上升" 的变化趋势。因素比较结果表明: 除蛋白酶的活性是非岩溶区的大于岩溶区外,其它的基本上都是岩溶区的大于非岩溶区;从降解率来看也是岩溶区的要稍高于非岩溶区。由此认为,秸秆在岩溶区土壤中的降解作用比非岩溶区更强。 

Effects of straw returning to field on enzyme activity in karst and non-karst area

In this paper the indoor simulation test is adopted to study the variation characteristics of soil pH,the rate of corn straw degradation and enzyme activity on brown rendzina in karst area and laterite in non-karst area in the degradation process of corn straw. The results show that:soil pH decreased in the early period,but increased in the late period; the largest degradation speed was mainly in the first 30 days,and then increased slowly,at the 98th day reached its balance; there were no significant changes in catalase,but the enzyme activity of invertase,urease,cellulose and protease showed a change tendency of "increase at the early stage,decrease at the middle stage and increase at the later stage". Factors comparison shows that:the activity of the protease in non-karst area is larger than that in karst area,but to other four kinds of enzyme activity,the results are reversed; the rate of corn straw degradation in karst area is also larger than non-karst area. Therefore,straw in the soil of karst area degrades more strongly.