长期有机培肥对南方红壤区稻田土壤碳循环功能基因的影响  

Effects of long-term organic fertilization on the functional genes of carbon cycle in paddy soils

作　　者：马慧霞 张桥 陈会巧 孙丽丽 周昌敏 顾文杰 卢钰升 徐培智[1,2] 解开治 MAHui-xia;ZHANG Qiao;CHEN Hui-qiao;SUN Li-li;ZHOU Chang-min;GUWen-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/Southern Key Laboratory of Plant Nutrition and Fertilizer,Ministry of Agriculture and Rural Development/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;Maoming Branch of Lingnan Modern Agricultural Science and Technology Guangdong Provincial Laboratory,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：《南方农业学报》2023年第5期1405-1416,共12页Journal of Southern Agriculture

基　　金：广东省科技计划项目(2021B1212050020);广东省现代农业产业技术体系创新团队项目(2023KJ118);广东省农业科学院农业优势产业学科团队建设项目(202121TD);广东省农业科学院低碳农业与碳中和研究中心项目(XT202220)。

摘　　要：【目的】研究长期有机培肥对南方红壤区稻田土壤碳循环功能基因的影响,为南方稻田土壤碳库高效利用和施肥策略提供理论参考。【方法】依托江西省红壤研究所长期定位试验平台,设4个处理:不施肥处理(CK)、单施化肥处理(NPK)、早稻施绿肥紫云英处理(M1)、早稻施绿肥紫云英+晚稻秸秆还田处理(M2)。晚稻收获后采集土壤样品,测定土壤基本理化性质,利用实时荧光定量PCR测定土壤碳循环功能基因的绝对定量,分析不同活性碳含量及碳循环相关基因与环境因子的关系。【结果】长期有机培肥处理提高了土壤有机碳组分中活性有机碳含量,其中M2处理易氧化有机碳、热水提取态有机碳、可溶性有机碳含量均显著高于CK(P<0.05,下同);M1处理土壤微生物量碳含量最高(193.98 mg/kg)。各处理中,M1和M2处理参与碳水解、碳固定和甲烷代谢过程的相关功能基因表达量均处于较低水平。相关分析结果表明,碳水解过程相关功能基因(除amyX、IsoP、lig和naglu)、碳固定过程相关功能基因(除mcrA)和甲烷代谢(除emGDH)与全钾、微生物量碳和胡富比均呈显著负相关。碳固定过程功能基因和甲烷代谢过程功能基因(除emGDH)与pH和速效钾呈正相关。随机森林分析结果显示,长期有机培肥稻田土壤对碳水解功能基因和环境因子的解释率为89.22%,对碳固定功能基因和环境因子的解释率为90.12%,对甲烷代谢功能基因和环境因子解释率为87.14%;结构方程建模结果表明,长期有机培肥稻田土壤中mnp和apu基因、mct和rbcL基因、em GDH和pmoA基因分别直接影响碳水解、碳固定和甲烷代谢过程,土壤有机碳、胡敏素和胡富比间接影响碳水解和碳固定基因表达量,胡敏酸、有机碳和胡敏素间接影响甲烷代谢过程功能基因表达量。【结论】长期有机培肥有利于增加南方稻田土壤活性有机碳组分含量,降低碳循环功能基�【Objectives】The study investigated the effects of long-term organic fertilization on the functional genes of soil carbon cycle in southern red soil areas,and provided theoretical reference for the efficient use of soil carbon pool and fertilization strategy in southern rice fields.【Method】Relying on the long-term positioning experimental platform of Jiangxi Red Soil Research Institute,four treatments were set:no fertilizer treatment(CK),single chemical fertilizer treat-ment(NPK),early rice green manure Astragalus sinicus L.treatment(M1),and early rice green manure A.sinicus+late rice straw return treatment(M2).Soil samples were collected after the harvest of late rice to determine the basic physical and chemical properties of soil.Real-time fluorescence quantitative PCR technique was used to determine the absolute quantification of soil carbon cycle functional genes,relationship between different active carbon contents and carbon cycle-related genes and environmental factors was analyzed.【Result】The results showed that the long-term organic fertilization treatment increased the content of reactive organic carbon in soil organic carbon fractions,of which the contents of easily oxidized organic carbon,hot water extracted organic carbon and soluble organic carbon were significantly higher in M2 treatment than in CK treatment(P<0.05,the same below);the microbial carbon content in the M1 treatment was the highest among the treatments(193.98 mg/kg).The abundance of functional genes involved in carbon hydrolysis,carbon fixation and methane metabolism was low in both M1 and M2 treatments.Correlation analysis showed that functional genes related to carbon hydrolysis(except amyX,IsoP,lig and naglu),carbon fixation(except mcrA)and methane metabolism(except emGDH)were significantly negatively correlated with total potassium,microbial carbon and humic acid/fulvic acid.Carbon fixation and methane metabolism(except emGDH)were positively correlated with pH and available potassium.Random forest analysis showed that lo

关 键 词：碳水解 碳固定 甲烷代谢 功能基因 有机培肥 

分 类 号：S154.1[农业科学—土壤学]