长期不同施氮量下微生物残体氮对土壤氮库稳定性和玉米氮素吸收的影响  

Impact of microbial residue nitrogen on soil nitrogen pool stability and maize nitrogen uptake under long-term varying nitrogen applications

作　　者：韩建 张玉铭[2] 何红波[3] 李俊娣 胡春胜[2] 李晓欣[2] 董文旭[2] 刘秀萍[2] 张丽娟[1] HAN Jian;ZHANG Yuming;HE Hongbo;LI Jundi;HU Chunsheng;LI Xiaoxin;DONG Wenxu;LIU Xiuping;ZHANG Lijuan(College of Resources and Environmental Sciences,Hebei Agricultural University,Baoding 071001,China;Center for Agricultural Re-sources Research,Institute of Genetics and Developmental Biology,Chinese Academy of Sciences/Hebei Provincial Key Laboratory of Soil Ecology/Key Laboratory of Agricultural Water Resources,Chinese Academy of Sciences,Shijiazhuang 050022,China;Institute of Ap-plied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;Hebei Provincial Key Laboratory of Food Safety,Shijiazhuang 050227,China)

机构地区：[1]河北农业大学资源与环境科学学院,保定071001 [2]中国科学院遗传与发育生物学研究所农业资源研究中心/河北省土壤生态学重点实验室/中国科学院农业水资源重点实验室,石家庄050022 [3]中国科学院沈阳应用生态研究所,沈阳110016 [4]河北省食品安全重点实验室,石家庄050227

出　　处：《中国生态农业学报（中英文）》2024年第5期766-779,共14页Chinese Journal of Eco-Agriculture

基　　金：国家重点研发计划项目(2022YFD1500302-3,2022YFD1901303-4);河北省重点研发计划项目(22326410D,21323601D);河北省自然科学基金项目(C2022503009)资助。

摘　　要：在农田生态系统中,化肥氮的施用是保障粮食高产稳产并维持土壤氮库稳定的重要管理措施,土壤微生物既是土壤氮素矿化的驱动者,也是土壤氮素固持的贡献者,在氮素保蓄和供应方面发挥着积极作用,直接影响作物的氮素吸收利用。本研究依托中国科学院栾城农业生态系统试验站小麦-玉米轮作农田14年长期不同施氮水平定位试验,选取玉米季施氮量150 kg(N)·hm^(-2)(N150)、200 kg(N)·hm^(-2)(N200)和300 kg(N)·hm^(-2)(N300)3个典型处理,通过微区施用15N标记氮肥,在收获期测定玉米产量、地上部总吸氮量和肥料氮吸收量,分析0~20 cm土层土壤全氮(TN)、微生物残体氮[MRN,包括真菌残体氮(FRN)和细菌残体氮(BRN)]、固定态铵(FN)、矿质氮(NH_4^(+)-N+NO_(3)^(-)-N,MN)和其他有机氮(ON)含量及不同氮库对^(15)N的截获,并通过多元回归分析和路径分析建立各形态氮库与玉米氮素吸收的相关关系,研究土壤“老氮”和肥料“新氮”在土壤氮库中的分配及其对作物吸收利用的影响,为研究区氮肥高效利用和地力培肥提供理论支撑。结果表明,玉米产量和氮素吸收以及土壤TN含量均以N200最高,此施氮量有利于作物高产和土壤氮库培育。N300的肥料氮吸收和残留量高于N200,表明N300的土壤氮“激发效应”强于N200,会诱导土壤“老氮”的更多矿化和损失,其土壤TN库稳定性差、更新程度较大。总氮库中,MRN占主导,N200显著高于其他处理,对TN的贡献均在50%以上,且FRN主导了MRN的累积。N200的土壤FRN∶BRN比值显著高于N150和N300,表明适宜施氮可显著提升真菌在氮素积累中的贡献,提升土壤氮库的稳定性;施氮不足(N150)或过量施氮(N300)提升了细菌在氮素积累中的贡献,不利于稳定土壤氮库。N300的MN和FN含量显著高于其他处理,表明过量施肥更多提升的是活性氮库。由此可见,适宜施氮可优化土壤氮库分配,促进更多的氮进�In farmland ecosystems,the application of chemical nitrogen(N)fertilizers is a crucial management strategy to ensure stable and high grain yields while maintaining the stability of soil N pools.Soil microorganisms play a pivotal role in both N mineralization and immobilization,thereby actively contributing to N retention and supply,which directly affects N uptake and utilization by crops.This study was conducted in the wheat-maize rotation field of the Luancheng Agro-Ecosystem Experimental Station of the Chinese Academy of Sciences.This study relied on a 14-year long-term positioning experiment with different N application rates.Three typical treatments were selected for N application rates during the maize season:150 kg(N)·hm^(-2)(N150),200 kg(N)·hm^(-2)(N200),and 300 kg(N)·hm^(-2)(N300).Micro-plots were used to apply ^(15)N-labeled N fertilizer to investigate the distribution of“old N”from soil and“new N”from fertilizer within soil N pools and their impact on crop N uptake and utilization.At harvest,the maize yield,total N uptake by the aboveground parts,and N uptake from fertilizers were measured.The contents of total N(TN),microbial residue N(MRN),fixed ammonium(FN),mineral N(NH_(4)^(+)-N+NO_(3)^(-)-N,MN),and other organic N(ON)in the 0-20 cm soil layer were analyzed,along with the interception of ^(15)N by different N pools.Multivariate regression and path analyses were used to establish the relationships between various N pool forms and maize N uptake.The results indicated that maize yield,N uptake,and soil TN content were the highest under the N200 treatment,favoring high crop yields and soil N pool cultivation.Fertilizer N uptake and residue were higher under the N300 treatment than under the N200 treatment,suggesting a stronger“priming effect”under the N300 treatment,which induces greater mineralization and loss of soil“old N”.The stability of soil TN pool was poor under the N300 treatment,with a higher degree of turnover.Among the TN pools,MRN was dominant,with the N200 treatment bein

关 键 词：玉米 施氮量 ^(15)N标记 吸氮量 土壤氮库 微生物残体氮 

分 类 号：S153[农业科学—土壤学] S154.36[农业科学—农业基础科学]