苹果专用肥对旱地果园土壤酶活性以及微生物多样性的影响

Effect of apple special fertilizer on soil enzyme activities and functional diversity of microbial community in a non-irrigated apple orchard

在10年生旱地红富士苹果园,研究了施用等养分(N、P2O5、K2O)量的无机肥(IF)、农家肥+无机肥(MIF)、苹果专用肥(ASF)后土壤养分、酶活性和微生物群落功能多样性的变化。结果表明,MIF和ASF处理显著提高了土壤有机质含量,分别较IF处理提高24.01%和21.07%,而土壤全氮含量在处理间无显著性差异;IF和ASF处理下土壤有效氮、速效磷和速效钾含量均高于MIF处理。MIF和ASF处理均显著提高了土壤过氧化氢酶、脲酶、蔗糖酶和碱性磷酸酶活性,且ASF处理下土壤脲酶和蔗糖酶活性亦显著高于MIF处理,分别增加18.97%和13.69%。ASF处理的土壤微生物群落平均颜色变化率(AWCD)、碳源利用丰富度指数(S)、物种丰富度指数(H)、优势度指数(D)均为最高;土壤微生物利用的碳源主要是糖类、多聚物类、氨基酸类和羧酸类,ASF处理显著提高了土壤微生物对羧酸类、多酚类和胺类的利用。主成分分析结果表明,不同施肥处理改变了土壤微生物碳源利用特征出现分异,对第一主成分(PC1)影响较大的碳源主要是糖类。不同施肥对果园土壤酶活性和微生物群落功能产生了显著影响,ASF处理更有利于提高土壤酶活性以及微生物群落功能多样性。

The characteristics of soil microbes are sensitive indicators of soil fertility. Fertilization can influence soil physiochemical and biological properties. The present study investigated the effect of inorganic fertilizer （ IF）, combination of manure and inorganic fertilizer （MIF） and ap- ple special fertilizer （ASF） at the equal N, P205 and K20 amount on soil nutrients, enzyme ac- tivities and functional diversity of microbial community based on Biolog technique in a 10-year- old Fuji apple orchard. The results showed that the MIF and ASF treatments significantly in- creased soil organic matter content by 24.01% and 21.07% compared with IF treatment, respec- tively, whereas there were not significant differences in soil total nitrogen content among treat- ments. The contents of soil available nitrogen, available phosphorus and available potassium in IF and ASF treatments were higher than those in MIF treatment. MIF and ASF treatments all signifi- cantly increased the activities of soil catalase, urease, invertase and alkaline phosphatase, and higher urease and invertase activities （ by 18.97% and 13.69%, respectively） were found under ASF treatment compared to MIF treatment. Average well color developments （AWCD）, substrate richness （S）, Shannon index （H）, and Simpson index （E） of microbial community were the highest in ASF treatment. The carbon sources mainly utilized by soil microorganisms were carbo-hydrates, polymers, amino acids and carboxylic acids, and ASF treatment significantly increased the utilization of carboxylic acids, polyphenols and amines by soil microbes. Principal Component Analysis （PCA） showed that fertilization could alter the carbon source use characteristics of soil microbial community, and carbohydrates were the determinant carbon sources that had a great impact on the first principal component （PC1）. Our results confirmed that different fertilization treatments exerted significant impacts on soil enzyme activities and microbial community function of apple orchard, and the application of ASF was better for the improvement of soil enzyme activities and functional diversity of microbial community.