长期低投入的稻鱼共作对土壤养分循环及有机碳库稳定性的影响  

Effects of long-term low-input rice-fish co-culture on soil nutrient cycling and organic carbon pool stability

作　　者：李龙燚 魏征 李谊慈 邹龙 何金峰 王华[1] 徐华勤[1] LI Longyi;WEI Zheng;LI Yici;ZOU Long;HE Jinfeng;WANG Hua;XU Huaqin(College of Environment and Ecology,Hunan Agricultural University,Changsha 410128,China)

机构地区：[1]湖南农业大学环境与生态学院,湖南长沙410128

出　　处：《华南农业大学学报》2024年第6期856-864,共9页Journal of South China Agricultural University

基　　金：国家自然科学基金区域创新发展联合基金重点项目(U21A20184)。

摘　　要：【目的】研究长期低投入稻鱼共作模式下土壤有机碳库和养分化学计量比等的变化,深入解析稻鱼模式的碳库变化,提升稻鱼模式生态功能。【方法】以湖南传统稻鱼共作代表县辰溪县的长期低投入稻鱼共作系统为研究对象,分析共作15年(RF15)和50年(RF50)稻鱼模式下土壤养分含量、理化性质、养分储量、有机碳组分、化学计量比和土壤碳库指数的变化,探讨关键影响因子。【结果】较之水稻单作(RM),RF15的有机碳、全氮、全磷、硝态氮、铵态氮、速效磷含量,有机碳储量、氮储量、磷储量,易氧化有机碳含量及其在有机碳中的占比均显著降低;C∶N、pH、颗粒有机碳含量、颗粒有机碳占比、矿质结合态有机碳含量占比、碳库活度和碳库活度指数分别显著增加47.98%、13.15%、35.47%、72.24%、31.68%、58.07%和58.07%。RF50的全氮含量、C∶P、N∶P、硝态氮含量分别显著增加13.13%、33.08%、14.31%和51.52%,全磷含量、容重、有机碳储量、磷储量、易氧化有机碳含量、矿质结合态有机碳含量及其占比均显著降低。RF15和RF50的碳库管理指数整体保持稳定,且均大于100。在长期稻鱼模式下,与土壤有机碳库稳定指标显著相关的环境因子为全氮含量、C∶N、有机碳储量。【结论】低投入的稻鱼模式系统虽然会导致养分流失,但自我维持时间的延长会使系统具备养分储量自我恢复的功能。长期稻鱼种养可以提升土壤质量,进而改善稻田生态环境。研究结果为优化稻鱼共作模式提供了理论依据,有助于提升该模式的生态功能和可持续性。【Objective】To investigate the changes in soil organic carbon pool,nutrient stoichiometric ratios and so on under a long-term low-input rice-fish co-culture system,deeply analyze the carbon pool dynamics in the rice-fish system,and enhance its ecological functions.【Method】The study focused on the long-term lowinput rice-fish co-culture system in Chenxi County,a representative county of traditional rice-fish co-culture in Hunan.The changes in soil nutrient content,physical-chemical property,nutrient storage,organic carbon component,stoichiometric ratio and carbon pool indexes within the rice-fish co-culture systems,which have been in operation for 15 years(RF15)and 50 years(RF50),were analyzed,and the key influencing factors were explored.【Result】Compared with rice monoculture(RM),RF15 showed significant reductions in soil organic carbon/total nitrogen/total phosphorus/nitrate nitrogen/ammonium nitrogen/available phosphorus contents,organic carbon storage/nitrogen storage/phosphorus storage,readily oxidized organic carbon content and its proportion in organic carbon;The C∶N,pH,particulate organic carbon content and its proportion,mineralassociated organic carbon content proportion,carbon pool activity,and carbon pool activity index increased significantly by 47.98%,13.15%,35.47%,72.24%,31.68%,58.07%,and 58.07%respectively.RF50 showed significant increases in total nitrogen content,C∶P,N∶P,and nitrate nitrogen content by 13.13%,33.08%,14.31%,and 51.52%respectively,while total phosphorus content,volume weight,organic carbon storage,phosphorus storage,readily oxidized organic carbon content,mineral-associated organic carbon content and its proportion decreased significantly.The carbon pool management indexes in RF15 and RF50 remained stable overall,and were both greater than 100.Under the long-term rice-fish model,the environmental factors significantly related to the stability index of soil organic carbon pool were total nitrogen content,C∶N,and organic carbon storage.【Conclusion】Although the

关 键 词：稻鱼共作 养分含量 养分储量 化学计量比 碳库管理指数 

分 类 号：S181[农业科学—农业基础科学] S154.1