长期施氮肥对黄棕壤微生物生物性状的影响及其调控因素  

Effects and associated regulatory factors of the microbial characteristics of yellow-brown soils following long-term nitrogen fertilization

作　　者：王静[1,2] 王磊[1] 刘耀斌[1,2] 章欢 张辉 汪吉东[1,2,3] 吴建燕[4] 张永春 WANG Jing;WANG Lei;LIU Yaobin;ZHANG Huan;ZHANG Hui;WANG Jidong;WU Jianyan;ZHANG Yongchun(Institute of Agricultural Resources and Environments,Jiangsu Academy of Agricultural Sciences/Scientific Observing and Experimental Station of Arable Land Conservation(Jiangsu),Ministry of Agriculture and Rural Affairs,Nanjing 210014,China;College of Resources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095,China;Institute of Agricultural Engineering,Jiangsu University,Zhenjiang 212023,China;Yantai Hongyuan Biological Fertilizer Co.,LTD,Yantai 264000,China)

机构地区：[1]江苏省农业科学院农业资源与环境研究所/农业农村部江苏耕地保育科学观测站,南京210014 [2]南京农业大学资源与环境科学学院,南京210095 [3]江苏大学农业工程学院,镇江212023 [4]烟台泓源生物肥料有限公司,烟台264000

出　　处：《中国生态农业学报（中英文）》2021年第5期833-843,共11页Chinese Journal of Eco-Agriculture

基　　金：江苏省自然科学基金项目(BK20190259);国家甘薯产业技术体系项目(CARS-10-B9);江苏省重点研发项目(BE2019378);国家重点研发项目(2018YFD0200505)资助。

摘　　要：基于黄棕壤小麦-甘薯轮作的长期定位试验,探究不同施氮处理土壤微生物生物量碳(MBC)、氮(MBN)含量和酶活性的变化及其潜在调控因子,为科学施氮提高土壤质量和改善土壤生态功能提供依据。试验选取始于2011年4个施氮处理:不施肥(CK)、不施氮肥(PK)、施化学氮肥(NPK)和化学氮肥配施有机肥(NPKM),调查两季作物收获后土壤MBC和MBN含量、酶活性及微生物碳氮利用效率的变化,并通过冗余分析(RDA)和结构方程模型(SEM)明确调控弱酸性黄棕壤中MBC和MBN变化的潜在因素。小麦和甘薯两季的结果表明:施氮肥降低了土壤MBC、MBN含量和蔗糖酶(SSC)、脲酶(SUE)活性,与NPK处理相比, NPKM处理增加了MBC、MBN含量和SSC、SUE活性。长期施用氮肥提高了土壤有机碳(SOC)和土壤养分[全氮(TN)和矿质态氮(MN)]含量,但施氮肥显著降低土壤p H以及微生物的碳氮利用效率。与小麦季相比,甘薯季土壤SOC和MN含量有所下降,而MBN含量和SSC活性有所升高。RDA和SEM结果表明,氮肥的施用强化了MBC与MBN、SSC与MBC以及SUE与MBC之间的关联性;不同施氮处理下土壤pH、有机碳、氮含量以及微生物的碳氮利用效率的变化直接或间接地影响土壤MBC、MBN含量和SSC、SUE活性,其中pH是调控土壤MBC变化的直接因素,而土壤SSC和SUE活性与MBC、MBN含量相互影响。长期施用氮肥降低了黄棕壤MBC、MBN含量和酶活性,化学氮肥配施有机肥有利于缓解生物性状的下降,土壤p H是影响MBC变化的主要因素,小麦-甘薯轮作中土壤微生物强烈的碳代谢过程利于增加MBN。Changes in soil microbial biomass C(MBC)and N(MBN)and their potential regulatory factors were investigated following long-term N fertilizer application since 2011 in a wheat-sweet potato rotation system.In the study,we aimed to provide a theoretical basis for the application of N fertilizers and to improve soil quality and ecological functions.Four N fertilization treatments were used:no fertilizer application(CK),no N-fertilizer application(PK),chemical N-fertilizer application(NPK),and chemical N-fertilizer combined with organic fertilizer application(NPKM).The soil MBC and MBN content,soil potential enzymes activities,and microbial C and N utilization efficiencies were investigated after the harvest of the two crops.Redundancy analysis and structural equation modeling were used to identify the potential biotic and abiotic factors that regulate MBC and MBN in the weakly acidic yellow-brown soils.The results showed that the contents of MBC and MBN and activities of sucrase and urease decreased in the N fertilization treatments.Compared with the NPK treatments,NPKM treatment increased the contents of MBC and MBN and the activities of sucrase and urease.Significantly higher contents of soil organic C(SOC),total N(TN),and mineral N(MN)were detected in the NPK and NPKM treated soils than in the CK and PK treated soils.However,long-term N fertilization significantly decreased the soil pH and efficiencies of microbial C and N utilization.Compared to the wheat season,the sweet potato season showed lower SOC and MN contents and higher MBN content and sucrase activity in the soils under all fertilization treatments.N fertilization strengthened the relationships between MBC and MBN and the sucrase and urease activities.Moreover,variations in the soil MBC and MBN contents and both sucrase and urease activities were regulated by soil pH,SOC and N content,and microbial C and N utilization efficiencies.Soil pH was the key factor driving the soil MBC content.Interactions were found between the activities of soil enzymes and th

关 键 词：黄棕壤 氮肥 微生物生物量 酶活性 潜在调控因子 

分 类 号：S181[农业科学—农业基础科学]