为探明喀斯特区玉米大豆带状复合种植对土壤理化性质及微生物群落结构多样性的影响,本研究设置玉米大豆间作(MSI)、玉米单作(MM)和大豆单作(SM)3种模式,采用Biolog-ECO微孔培养法,旨在揭示玉米大豆种植模式对土壤微生物碳源代谢活性、多样性以及土壤性质的影响及其机制.结果表明,与MM及SM相比,MSI土壤微生物群落丰富度指数(McIntosh index)分别显著提高了11.90％和58.40％,平均颜色变化率(average well color develop-ment,AWCD)分别显著增加了24.50％和80.10％,羧酸类、氨基酸类和酚酸类碳源的平均相对吸光度分别显著提高了34.50％、63.70％和61.80％;碳源代谢指纹图谱表明,MSI模式中土壤微生物通过提高衣康酸的代谢活性进而增加了对羧酸类碳源的利用,通过提高L-苯丙氨酸、L-苏氨酸和甘氨酰-L-谷氨酸的代谢活性从而增加了氨基酸类碳源利用,通过提高吐温40、吐温80和肝糖的代谢活性从而增加了对多聚类碳源的利用;同时,MSI处理土壤SOC分别较MM和SM显著提高8.50％和72.84％,NH4+-N和TN含量分别较SM处理显著增加46.70％和33.30％;主成分分析表明,提取的2个主成分解释了碳源利用总变异的79.69％,种植模式对碳源代谢的综合利用能力表现为MSI>MM>SM,其中MSI土壤微生物群落对羧酸类、氨基酸类和多聚类代谢利用能力最强;冗余分析则表明,显著影响碳源代谢利用的2个环境因子分别是TN(53.50％)和SOC(30.90％),其中TN促进了羧酸类和氨基酸类碳源的代谢利用,SOC加强了胺类和酚酸类碳源的利用.综上可见,玉米大豆间作模式土壤微生物碳代谢的偏好性主要由微生物群落结构多样性引起,同时又受土壤全氮和有机质含量的调控,表明微生物群落结构与土壤理化因子间的互作可能是大豆玉米复合种植增产增效的一个关键因素.
Effects of maize and soybean intercropping on soil physicochemical properties and microbial carbon metabolism in karst region
This study aimed to investigate the effects of corn and soybean belt intercropping on soil physicochemical prop-erties and microbial community structure diversity in a karst area.Three planting models were established:corn and soy-bean intercropping (MSI),corn monocropping (MM),and soybean monocropping (SM).The Biolog-ECO microplate method was used to explore the impacts of these different planting patterns on the metabolic activity,diversity,and soil properties of soil microbial carbon sources,as well as their underlying mechanisms.The results showed that compared to MM and SM,the MSI model significantly increased the soil microbial community richness index (McIntosh index) by 11.90％ (P<0.05) and 58.40％ (P<0.01),respectively,and the AWCD value by 24.50％ and 80.10％,respectively.The relative absorbance of carboxylic acids,amino acids,and phenolic acids increased significantly by 34.50％,63.70％,and 61.80％ on average,respectively.The carbon source metabolic fingerprint revealed that the MSI model enhanced the utili-zation of p-carboxylic acid carbon sources by increasing the metabolic activity of itaconic acid,and improved the utiliza-tion of amino acid carbon sources by boosting the metabolic activity of L-phenylalanine,L-threonine,and glycyl-glutamic acid.Additionally,the MSI model increased the utilization of polymer carbon sources via enhanced metabolic activity of Tween 40,Tween 80,and liver sugar.Furthermore,soil SOC under MSI treatment was significantly higher by 8.50％ and 72.84％ compared to MM and SM,respectively,while NH4+-N and TN contents were significantly increased by 46.70％ and 33.30％ compared to SM treatment,respectively.Principal component analysis revealed that the two extracted components explained 79.69％ of the total variation in carbon source utilization.The overall carbon source metabolic capacity followed the order MSI>MM>SM,with the MSI soil microbial community demonstrating the strongest metabolic utilization of carboxylic acids,amino acids,and polymers.Redundancy analysis indicated that TN (53.50％) and SOC (30.90％) were the two most significant environmental factors influencing carbon source metabolic utilization.TN promoted the metabolic utilization of carboxylic acid and amino acid carbon sources,while SOC enhanced the utilization of amine and phenolic acid carbon sources.The preferential carbon metabolism observed in maize and soybean intercropping was primarily driven by the diversity of microbial community structure,and was further regulated by soil total nitrogen and organic matter con-tent.These findings suggest that the interaction between microbial community structure and soil physicochemical proper-ties may play a key role in the yield improvement and efficiency of soybean and corn intercropping systems.
maizesoybeansoil microorganismmetabolic activity of carbon sourcephysical and chemical properties of soilBiolog-ECO
万方数据
维普
