中国土壤与肥料Issue(11)：1-8,8.DOI:10.11838/sfsc.1673-6257.25090
我国亚热带地区林地开垦为茶园后的土壤氮保持能力下降
Decline in soil nitrogen retention capacity after converting subtropical forest land to tea plantations in China
摘要
Abstract
Understanding the transformation rate of soil nitrogen and its availability in tea plantations was crucial for guiding nitrogen fertilizer application and assessing environmental impacts during tea cultivation.Using paired labeling with 15NH4NO3 and NH415NO3 combined with a nitrogen transformation model,this study investigated changes in soil nitrogen transformation processes ten years after converting forest land to tea plantations.The results showed that after converting forest land to tea plantations,soil activated carbon(SOC)and C/N significantly were decreased due to fertilization,while pH and Ca,Mg levels significantly were increased.Compared to forest land,the mineralization rate of organic nitrogen in tea plantation soil was significantly decreased,while heterotrophic nitrification showed no significant difference,indicating a significant decline in inorganic nitrogen supply capacity in tea plantation soil.The autotrophic nitrification rate was significantly increased,while the microbial assimilation rate of NO3-was significantly decreased,leading to a significant increase in the net production rate of NO3-(with forest land and tea plantation soil rates being N 1.14 and 2.37 mg·kg-1·d-1,respectively).The microbial assimilation and adsorption rates of NH4+significantly was decreased,indicating that mineralized nitrogen was primarily consumed through autotrophic nitrification.The high production and low consumption of nitrate nitrogen led to a significant increase in the potential for NO3-production,but the retention capacity of nitrate nitrogen in tea plantation soil significantly was decreased(forest land soil's NO3-retention capacity was about nine times that of tea plantation soil),increasing the risk of NO3-leaching in tea plantation soil.Additionally,correlation analysis between soil physicochemical properties and nitrogen transformation rates revealed that soil nitrogen retention capacity was positively correlated with SOC,C/N,water holding capacity and CEC,and negatively correlated with pH,Ca,Mg,P,Free Fe and Free Al,suggesting that the decline in soil nitrogen retention capacity was related to excessive fertilization in tea plantations.It was recommended to apply fertilizers rationally to improve nitrogen use efficiency and reduce the risk of NO3-leaching.关键词
茶园/林地/氮素转化模型/氮转化速率/NO3-保持Key words
tea plantation/forest land/nitrogen transformation model/nitrogen transformation rate/NO3-retention引用本文复制引用
HAO Yu-pei,MIAO Xiong-yi,GUO Qi..我国亚热带地区林地开垦为茶园后的土壤氮保持能力下降[J].中国土壤与肥料,2025,(11):1-8,8.基金项目
云南省基础研究计划-面上项目(202501AT070037) （202501AT070037）
云南省地质矿产勘查开发局科技创新项目(云地[2025])8号 （云地[2025]）
贵州省基础研究计划面上项目(黔科合基础MS[2025]269) （黔科合基础MS[2025]269）
贵州省教育厅高等学校自然科学研究项目(黔教技[2024]309号) （黔教技[2024]309号）
安顺职业技术学院院级基金项目重点课题(安职院重点基金合X202302号). （安职院重点基金合X202302号）
