神东矿区复垦地土壤酶活性变化和分布特征

Distribution and changes of soil enzyme activities in reclaimed minging land

土壤酶活性可用于衡量土壤养分供应能力及土壤质量,而其季节变化可反映养分供应与植物需求的耦合关系。以马家塔矿复垦地为研究对象,对不同植物群落下土壤酶活性的季节变化进行了监测,结果表明:复垦土壤的表层过氧化氢酶、脲酶、磷酸酶和蔗糖酶活性均显著高于下层和对照的原状土壤,说明复垦可以提高土壤的酶活性。不同植被下土壤的酶活性大小总体上以苜蓿、油蒿、桧柏和侧柏对土壤质量的贡献较大。4种酶活性的动态变化趋势基本相同,都表现为前期先增加,增加到最大值后又开始下降,总体上均以夏季(7-8月份)活性最高。酶活性的变化和大小可以体现有机质含量的变化和转化方向,也能体现基础氮素的变化方向,复垦后酶活性提高,但是和农田土壤相比还有一定差距,所以复垦工作还需继续开展。

Soil quality and supply capacity of soil nutrients can be measured by soil enzyme activities.The seasonal changes of soil enzyme activities can reflect the relationship between the nutrient supply and plant demand.Taking reclamation of Majiata mine as test objects,we studied the seasonal changes of soil enzyme activities under different vegetations.The results were as follows： Enzyme activities（catalase、urease、alkaline and phosphatase invertase） in topsoil of reclamation areas were significantly higher than subsoil and CK.Soil enzyme activities under different vegetations were not the same.Medicago sativa、Artemisia ordosica Kraxch、S.vulgaris Ant and Platycladus orientalis（Linn.）Franco contributed greatly to the quality of the soil.Dynamic of four kinds of enzyme activities had the same trends.Enzyme activities were the highest in summer.Changes of soil enzyme activities could reflect the change and transfer direction of soil organic matter and nitrogen.Soil enzyme activities in reclaimed land lagged behind that of cropland.So the reclamation work needed to continue doing.