盐渍化土壤酶活性及其与微生物、理化因子的关系

为探讨盐渍化土壤酶活性分布特征及其与土壤微生物量、理化性质的关系,选择了土默川平原不同盐渍化程度(轻度、中度和重度盐渍化)土壤为研究对象。运用简单相关、典型相关和主成分分析法,对0~40 cm土层土壤酶活性与土壤微生物量、理化因子两组变量间的相关性进行了分析。结果表明:土壤蔗糖酶、脲酶、碱性磷酸酶活性均随土层深度增加减少,其酶活性变化范围分别为0.65~36.55 mg/g、0.003~0.018mg/g、0.10~0.98 mg/g,土壤过氧化氢酶活性随土层深度增加而增大,其变化范围在2.76~3.35 mg/g之间;随盐渍化程度加重土壤4种酶活性均降低,且不同盐渍化程度土壤4种酶活性月份间差异显著;土默川平原盐渍化土壤酶活性与土壤微生物量、土壤理化性质这两组变量间均有显著的典型相关变量存在,且均能代表变量总体的相关信息;其典型相关主要是土壤p H、有机质、含水量、速效磷、速效钾和4种土壤酶活性引起的。土壤酶活性和土壤微生物量的典型相关主要是由土壤蔗糖酶、脲酶和土壤微生物量中的固氮菌数量、细菌数量、真菌数量引起的;主成分分析认为,土壤有机质、碱性磷酸酶、蔗糖酶、放线菌、纤维素分解菌和土壤含水量等可作为影响土默川平原盐渍化土壤肥力特性的重要因子。

Enzyme Activities of Saline-alkali Soil and its Relationship with Soil Microbial Biomass and Physicochemical Factor

In order to investigate the soil layer enzyme activity, distribution traits characteristics, and their relation with soil microbial biomass, physicochemical characteristics, this study took 3 soil types with different salinization levels (light, moderate, high) in Tumochuan plain as research objectives to analyze the correlation between soil enzyme activities, microbial biomass and physicochemical characteristics of 0~40 cm layer soils, by canonical correlation and typical correlation, and principal component analysis methods. The results showed that soil invertase, urease and alkaline activities decreased with the increase of soil depth. Their variation rates were 0.65~36.55 mg/g, 0.003~0.018 mg/g and 0.10~0.98 mg/g, respectively. While soil catalase activity increased with the increase of soil depth, and the changing rate was 2.76~3.35 mg/g. Soil invertase, catalase, urease and alkaline phosphatase activities decreased with the increase of total salt content, but soil enzyme activities were significantly different in different salt affected soils and during different seasons. There were obvious canonical correlation between soil enzyme activity and soil physicochemical properties, soil microbe quantity, basically representing general correlation between variables. The correlation between soil enzyme activity and soil physicochemical properties was mainly attributed to pH, organic matter-moisture content, available phosphorus and available potassium of physicochemical factors and invertase, catalase, urease and alkaline phosphatase; while the correlation between soil enzyme activity and soil microbe quantity was to invertase, urease of soil enzyme activities and bacteria, fungi, azotobacter of microbe quantities. The principal component analysis reflected that organic matter, alkaline phosphatase, invertase, actinomyces, cellulose decomposing bacteria and moisture content could be considered as the most important factors affecting soil fertility in Tumochuan plain.