柏木低效林改造对土壤微生物、酶活性及养分的影响

Effects of Transformation of Cypress funebris Forest on Soil Microorganism,Enzymatic Activity and Nutrient

为了解不同改造模式对柏木低效林的改造效果,以德阳市旌阳区柏木(Cupressus funebris)低效林(简称纯柏)为对照,对4种改造模式(核桃+无植草、核桃+菊苣、核桃+苜蓿、核桃+鸭茅)的土壤微生物、酶活性及土壤养分进行了测定和分析。结果表明:与纯柏相比,4种改造模式均能不同程度提高土壤微生物数量、酶活性及养分(P、K)含量,各个改造模式中的土壤微生物总数、蔗糖酶、碱性磷酸酶及有效磷与纯柏差异显著;土壤微生物数量、酶活性及养分各指标含量间相关关系不同,其中,土壤微生物之间相关性不显著,土壤蔗糖酶与过氧化氢酶、脲酶呈显著正相关,其余酶活性之间相关性不显著,土壤有机质、全氮、碱解氮及p H之间、土壤全钾与速效钾、全磷及有效磷之间均呈显著正相关。土壤肥力分析表明,3种林草复合模式均能有效提高土壤肥力,核桃+菊苣模式改造效果最佳。

In order to understand the impacts of forest transformations on Cypress funebris forest by several typical transformation patterns（ walnut＋no grass,walnut＋chicory,walnut＋alfalfa,walnut＋orchardgrass）,the soil microorganism,enzymatic activity and nutrient were determined and analyzed in different patterns of transformation when C. funebris forest being used as a control in Jingyang District,Deyang City. Four transformation models increased the amount of soil microorganism,enzyme activities and soil nutrient（ P and K） in different degree compared with C. funebris forest. The differences of total amount of microorganism between typical patterns of transformation and C. funebris forest were significant,so were the soil sucrose activity,alkaline phosphatase activity and available P. There were different relationships among the soil microorganism,enzyme activity and nutrient,for example,the correlations among soil microorganism were not significant,and significantly positive correlation relationships between the soil sucrose and catalase,urease were observed,while there were no significant correlations among the rest of the enzyme activities,and there were significant positive correlations among organic matter,total N,hydrolysis N and pH. Total K had a significantly positive correlation to rapidly-available K,total P and effective P. Through the soil fertility analysis,three kinds of forest and herbage composite patterns could improve the soil fertility effectively,and the walnut＋chicory was the best.