长期不同施肥对番茄根际土壤微生物功能多样性的影响

Effects of various long-term fertilization regimes on soil microbial functional diversity in tomato rhizosphere soil

研究长期定位施肥对番茄根际土壤微生物群落功能多样性的影响,旨在为番茄根际生态过程中的调控提供科学依据和理论指导。以沈阳农业大学长期定位施肥基地的番茄根际土壤为研究对象,采用Biolog-ECO微平板法,分析了11个处理:N(单施氮肥)、K(单施钾肥)、P(单施磷肥)、NP(氮磷肥配施)、NPK(氮磷钾肥配施)、MN(有机肥配施氮肥)、MK(有机肥配施钾肥)、MP(有机肥配施磷肥)、MNP(有机肥配施氮磷肥)、MNPK(有机肥配施氮磷钾肥)、对照CK(不施肥)的土壤微生物群落功能多样性。结果表明:(1)配施有机肥能够显著提高土壤有机质、速效磷、速效钾和碱解氮的含量,氮肥的施入会降低根际土壤的pH,各处理间土壤理化性质的差异显著;(2)配施有机肥可以增强番茄根际土壤微生物对碳源的利用能力,提高微生物群落功能多样性,其中,MNP处理微生物对碳源利用能力最强,微生物活性最高。具体表现为:(1)长期施肥改变了土壤微生物对碳源的利用能力。配施有机肥处理的土壤微生物对6类碳源的总利用能力高于单施化肥处理,以MNP优势最明显;(2)在6类碳源中,氨基酸类碳源利用能力最强,酚酸类碳源利用能力最弱;(3)主成分分析表明,31种碳源对PC1贡献较大的有12种,对PC2贡献较大的有8种;(4)施加肥料的处理的Shannon指数、丰富度指数和优势度指数均高于不施肥的处理,但其均匀度下降。有机肥配施氮磷肥处理的Shannon指数、丰富度指数均显著高于其他处理。综合所有结果,以MNP的施肥较果最佳,能够呈现较高的根际土壤微生物功能多样性。

The effects of long-term fertilization on the functional diversity of the soil microbial community in tomato rhizosphere were studied. The goal of study was to provide scientific basis and theoretical guidance for the regulation of ecological processes in the tomato rhizosphere. In this study, soil was sampled from a protected vegetable field that had been fertilized for 29 years in Shenyang Agricultural University, and 11 treatments were chosen, including a no fertilization control （CK）, and fields receiving nitrogen （N）, phosphate （P）, potassium （K）, nitrogen phosphate （NP）, nitrogen phosphate potassium （NPK） fertilizers, and their combined application with organic manure （MN, MK, MP, MNP, and MNPK, respectively）. Biolog ECO-plate methods were used to analyze the soil microbial community functional diversity. The results showed that 1） organic manure significantly increased the content of soil organic matter, available P, available K, and available N, the application of N fertilizer decreased the pH of rhizosphere soil, and the difference in soil physical and chemical properties was significant. 2） The application of organic manure enhanced the ability of soil microbes in the tomato rhizosphere soil to utilize and improve the functional diversity of the microbial community. Among them, soil microbial use of carbon sources and microbial activity of the MNP treatment were the highest and greatest, respectively. Specific performances were as follows：① long-term fertilization changed the soil microbial use of carbon sources. The total utilization of six kinds of carbon sources was higher than that of single chemical fertilizers, and that of MNP was the greatest. ② In the six carbon sources, the utilization rate of amino acids was the highest, and the utilization rate of phenolic acid was the lowest. ③ Results of principal component analysis showed that there were 12 kinds of carbon sources with large contributions to PC1 and eight for PC2 out of 31 kinds of carbon sources. ④ Shannon index, richness index, and the dominance index of fertilizer treatments were higher than those without fertilization, but the uniformity decreased. The Shannon index and abundance index of MNP were significantly higher than that of other treatments. Based on all the results, we concluded that MNP fertilization was the best and could result in higher rhizosphere soil microbial functional diversity.