摘要
【目的】微生物在土壤氮循环过程中发挥着重要作用。通过研究农田土壤氮循环过程中不同功能微生物群落基因丰度对施肥模式的响应及其关键影响因素,探讨不同施肥模式调控下氮素转化的微生物学机制,为改善农业生产中氮素的管理策略提供理论依据。【方法】田间试验始于2011年,试验地点位于江苏省常州市溧阳市南渡镇,供试土壤为白土型水稻土,种植制度为稻麦轮作。试验包括单施化肥(NPK)、化肥+畜禽有机肥(NPKM)、化肥+秸秆还田(NPKS)以及相邻江苏省耕地质量监测点不施肥对照(CK),共4个处理。于2014年水稻成熟期采集土壤样品,采用实时荧光定量PCR法分析了土壤硝化(amoA)、反硝化(narG、nirS、nirK、norB、nosZ)、固氮(nifH)、硝酸盐异化还原(napA)等氮循环过程的相关功能微生物基因丰度的变化。以氨氧化微生物为模式微生物,测定添加与不添加1-辛炔情况下的土壤硝化潜势,分析氨氧化古菌(AOA)与氨氧化细菌(AOB)功能基因丰度与土壤硝化功能的内在联系。【结果】与CK相比,NPK处理显著增加了土壤中AOBamoA、narG、nosZ和nifH基因的丰度。与NPK处理相比,NPKS处理进一步提高了土壤中AOB-amoA、narG、nosZ、nifH以及nirK基因的丰度。与CK相比,除AOA-amoA、nirS、napA基因以外,NPKM处理显著提高了土壤中所有氮循环功能基因的丰度。AOB-amoA基因丰度的变化对土壤氮循环功能基因丰度的整体变异影响最大。AOB主导了施肥土壤的硝化过程(81.90%~84.42%)。土壤总硝化潜势与AOB-amoA基因丰度显著相关,但与AOA-amoA基因丰度相关性不显著。氮循环功能微生物基因丰度主要受到土壤pH、土壤有机碳(SOC)和NO3–含量的影响。【结论】畜禽有机肥与秸秆的施用能够进一步刺激氮循环功能基因丰度的增长,促进土壤氮循环。土壤pH、SOC和NO_(3)^(–)含量是影响土壤氮循环功能微生物丰度的关键因素
【Objectives】Soil microorganisms play important roles in nitrogen cycle.This study aimed to enhance our understanding of the microbial mechanism of soil nitrogen transformation and provide a theoretical basis for improving nitrogen management strategies in agricultural soils.Thus,we analyzed the response of different functional genes in nitrogen cycle under different fertilization managements.【Methods】Soils subjected to four different short-term fertilization managements[no fertilizer(CK),mineral NPK fertilizer only(NPK),mineral NPK plus livestock manure(NPKM),and mineral NPK fertilizer plus wheat straw(NPKS)]were collected from a field experiment.Quantitative real-time PCR was used to determine the variation of abundances of functional genes involved in soil nitrification(amoA),denitrification(narG,nirS,nirK,norB,nosZ),nitrogen fixation(nifH)and dissimilatory nitrate reduction(napA)pathways under the different fertilization managements.The relationships between the functional gene abundances of ammonia-oxidizers(AOA and AOB)and soil nitrification were analyzed by measuring nitrification potential with and without 1-octyne.【Results】Compared with CK,NPK treatment significantly increased the abundances of AOB-amoA,narG,nosZ,and nifH genes in soil.Compared with NPK,NPKS treatment increased the abundances of AOB-amoA,narG,nosZ,nifH and nirK genes in soil.Compared with CK,NPKM treatment increased the abundances of all the nitrogen cycling genes,except AOA-amoA,nirS and napA genes.AOB-amoA genes abundance contributed most to the variations in the abundance of all nitrogen cycling related genes in the fertilization managements.AOB dominantly contributed(81.90%-84.92%)to nitrification in all the fertilized soils.The abundance of AOB-amoA gene rather than that of AOA-amoA gene was significantly correlated with soil nitrification potential.Soil pH,SOC and NO_(3)^(-) significantly affected the nitrogen cycling microbial community abundance.【Conclusions】The application of livestock manure and straw have strong
作者
郭俊杰
朱晨
刘文波
王建中
凌宁
郭世伟
GUO Jun-jie;ZHU Chen;LIU Wen-bo;WANG Jian-zhong;LING Ning;GUO Shi-wei(College of Resources and Environmental Sciences,Nanjing Agricultural University/Jiangsu Provincial Key Laboratory of Solid Organic Waste Utilization,Nanjing 210095,China;Station of Comprehensive Agricultural Service in Nandu Town,Liyang City,Changzhou 213371,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2021年第5期751-759,共9页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金项目(31902114)
中央高校基本科研业务费专项资金(KJQN202019)
中国博士后科学基金项目(2019M651861)。
关键词
施肥
氮循环
功能基因
土壤功能
fertilization
nitrogen cycle
functional gene
soil function
