长期培肥降低稻田土壤硝化和反硝化细菌功能基因丰度并减缓氮素周转  

Long-term fertilization reduces nitrifying and denitrifying functional gene abundance and slows down the nitrogen recycle in paddy soils

作　　者：陈会巧 马慧霞 张桥 孙丽丽 周昌敏 顾文杰 卢钰升 徐培智[1,2] 解开治 CHEN Hui-qiao;MA Hui-xia;ZHANG Qiao;SUN Li-li;ZHOU Chang-min;GU Wen-jie;LU Yu-sheng;XU Pei-zhi;XIE Kai-zhi(College of Resources and Environmental Science,Gansu Agricultural University,Lanzhou,Gansu 730070,China;Institute of Agricultural Resources and Environment,Guangdong Academy of Agricultural Sciences/Key Laboratory of Plant Nutrition and Fertilizer in South Region,Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Nutrient Cycling and Farmland Conservation/Guangdong Engineering Research Center of Soil Microbes and Cultivated Land Conservation,Guangzhou,Guangdong 510640,China;Guangdong Agricultural Environment and Cultivated Land Quality Protection Center,Guangzhou,Guangdong 510500,China;Lingnan Modern Agricultural Science and Technology Guangdong Province Laboratory Maoming Branch,Maoming,Guangdong 525000,China)

机构地区：[1]甘肃农业大学资源与环境学院,甘肃兰州730070 [2]广东省农业科学院农业资源与环境研究所/农业农村部南方植物营养与肥料重点实验室/广东省养分资源循环利用与耕地保育重点实验室/广东省土壤微生物与耕地保育工程技术研究中心,广东广州510640 [3]广东省农业环境与耕地质量保护中心,广东广州510500 [4]岭南现代农业科学与技术广东省实验室茂名分中心,广东茂名525000

出　　处：《植物营养与肥料学报》2023年第9期1630-1642,共13页Journal of Plant Nutrition and Fertilizers

基　　金：广东省科技计划项目(2021B1212050020);广东省农业科学院低碳农业与碳中和研究中心项目(XT202220);广东省农业科学院农业优势产业学科团队建设项目(202121TD);广东省现代农业产业技术体系创新团队项目(2022KJ118);广东省农业科学院中青年学科带头人培养计划项目(R2020PY-JG012);广东省农业科学院汕尾分院科技合作专项(2021-分院专项-02);茂名实验室科研启动项目(2021TDQD002)。

摘　　要：【目的】硝化和反硝化细菌在稻田土壤氮循环中起着十分重要的作用。研究长期有机物料还田条件下红壤区稻田土壤硝化和反硝化细菌群落及功能基因丰度,有助于揭示土壤硝化和反硝化过程中的微生物机制,为红壤区稻田氮高效利用和管理提供参考。【方法】基于40年水稻长期施肥定位试验,选择其中的不施肥(CK)、单施化肥(NPK)、早稻施绿肥紫云英(M1)和早稻施绿肥紫云英+晚稻秸秆还田(M2)处理小区采集土壤样品,利用宏基因组测序和荧光定量PCR技术,通过对典型反硝化细菌nirK、nirS和硝化细菌amoA、hao进行基因标记,分析了土壤硝化和反硝化细菌群落结构和多样性。【结果】nirK、nirS型反硝化细菌和AOB(amoA)、hao细菌主要隶属于变形菌门(Proteobacteria)。所有处理中nirK型反硝化细菌的优势属为Ardenticatena菌属、硝化螺菌属(Nitrospira)和罗河杆菌属(Rhodanobacter),且M2处理土壤中罗河杆菌属相对丰度显著高于其他处理(P<0.05)。nirS型反硝化细菌中类固醇杆菌属(Steroidobacter)和慢生根瘤菌属(Bradyrhizobium)分别在M2和NPK处理中占比最高,分别达到33%和29%。AOB(amoA)细菌中慢生根瘤菌(Bradyrhizobium)在CK和M1处理中占比最高,分别为30%和32%;变形菌门中的甲基单胞菌属(Methylomonas)在M2处理中占比最大;硝化螺菌属(Nitrospira)在CK处理中的占比显著高于其他处理。hao细菌中地杆菌属(Geobacter)相对丰度在各处理中占比最高。冗余分析显示,土壤速效氮(P=0.002)、有效磷(P=0.006)和有机碳(P=0.002)是nirK型和nirS型反硝化细菌群落组成变化的主导因子,土壤有机碳(P=0.008)、有效磷(P=0.01)、速效钾(P=0.008)是hao细菌群落结构变化的关键因子,速效氮(P=0.004)、有效磷(P=0.004)和全磷(P=0.002)是AOB(amoA)群落结构产生变化的关键因子。Spearman相关性分析表明,土壤有机碳、全氮和铵态氮与功能基因amoA、hao和反硝化功能�【Objectives】Nitrifying and denitrifying bacteria play important roles in nitrogen cycle in paddy soil.We studied the variation of nitrifying and denitrifying bacterial communities and abundance of functional genes after long-term organic material return,to provide a reference for efficient utilization and management of nitrogen in paddy soil in red soil area.【Methods】Soil samples were taken from four treatment plots in a long-term positioning experiments that had lasted for 40 years,they were:no fertilizer input control(CK),only chemical fertilizer application(NPK),returning Astragalus smicus to early rice(M1),and returning Astragalus smicus to early rice field and return straw to late rice field(M2).Metagenomic sequencing and fluorescent quantitative PCR technology through marker genes(amoA,nirK,nirS and hao)were used to analyze the community structure and diversity of nitrification and denitrification bacteria.【Results】Most nirK,nirS denitrifying bacteria and AOB(amoA),hao bacteria belong to Proteobacteria.In all the tested treatments,the dominant genera of nirK-type denitrifying bacteria were Ardenticatena,Nitrospira and Rhodanobacter,and the relative abundance of Rhodanobacter was significantly higher in M2 than in other treatments(P<0.05).Steroidobacter and Bradyrhizobium accounted for 33%and 29%of the total nirS-type denitrifying bacteria in M2 and NPK treatments,respectively.Among AOB(amoA)bacteria,Bradyrhizobium had the highest proportion in CK and M1 treatments,accounting for 30%and 32%,respectively.Methylomonas in Proteobacteria had the largest proportion in M2 treatment.The proportion of Nitrospira was significantly higher in CK than in the other treatments.Geobacter was recorded the highest relative abundance among hao bacteria in all the treatments.The redundancy analysis showed that soil available N(P=0.002),available P(P=0.006)and organic carbon(P=0.002)were the main factors driving the changes in community composition of nirK-type and nirS-type denitrifying bacteria.Soil organic carbon

关 键 词：长期施肥 稻田土壤 硝化微生物 反硝化微生物 功能基因 

分 类 号：S154.3[农业科学—土壤学]