摘要
明确茶园土壤氮素转化速率及其氮素有效性有助于指导茶树种植过程中氮肥施用及其环境效应。采用^(15)NH_(4)NO_(3)和NH_(4)^(15)NO_(3)成对标记法结合氮素转化模型研究林地开垦种植茶树10年后土壤氮转化过程的变化。结果表明,林地开垦种植茶树后,受施肥影响,土壤活性炭(SOC)、碳氮比(C/N)显著下降,但pH和全Ca、全Mg等含量显著升高。与林地相比,茶园土壤有机氮矿化速率显著下降,而异养硝化没有显著差异,表明茶园土壤无机氮供应能力显著下降;自养硝化速率显著升高,而NO_(3)^(-)微生物同化速率显著下降,导致NO_(3)^(-)净产生速率显著升高(林地和茶园土壤分别为N 1.14和2.37 mg·kg^(-1)·d^(-1));NH_(4)+微生物同化速率和吸附速率显著下降,表明矿化产生的铵态氮主要通过自养硝化过程消耗。硝态氮的高产生和低消耗导致NO_(3)^(-)产生潜势显著升高,但茶园土壤硝态氮保持能力显著下降(林地土壤NO_(3)^(-)保持能力约是茶园土壤的9倍),导致茶园土壤NO_(3)^(-)的淋失风险随之提高。另外,通过对土壤理化性质与氮转化过程速率的相关性分析得出,土壤氮保持能力与SOC、C/N、田间持水量、阳离子交换量等呈正相关,与pH、Ca、Mg、P、游离Fe、游离Al等呈显著负相关,说明土壤氮保持能力下降与茶园过量施肥有关。建议合理施肥,以提高氮素利用率,降低NO_(3)^(-)淋失风险。
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 ^(15)NH_(4)NO_(3) and NH_(4)^(15)NO_(3) 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 NO_(3)^(-)was significantly decreased,leading to a significant increase in the net production rate of NO_(3)^(-)(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 NH_(4)+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 NO_(3)^(-)production,but the retention capacity of nitrate nitrogen in tea plantation soil significantly was decreased(forest land soil’s NO_(3)^(-)retention capacity was about nine times that of tea plantation soil),increasing the risk of NO_(3)^(-)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 NO_(3)^(-)leaching.
作者
郝玉培
缪雄谊
郭琪
HAO Yu-pei;MIAO Xiong-yi;GUO Qi(Department of Modern Engineering,Anshun Technical College,Anshun Guizhou 561000;Key Laboratory of Sanjiang Metallogeny and Resources Exploration and Utilization Ministryof Natural Resources,Kunming Yunnan 650051;Yunnan Key Laboratory of Sanjiang Metallogeny and ResourcesExploration and Utilization,Kunming Yunnan 650051;School of Geography and Environmental Science,GuizhouNormal University,Guiyang Guizhou 550025)
出处
《中国土壤与肥料》
北大核心
2025年第11期1-8,共8页
Soil and Fertilizer Sciences in China
基金
云南省基础研究计划-面上项目(202501AT070037)
云南省地质矿产勘查开发局科技创新项目(云地〔2025〕)8号
贵州省基础研究计划面上项目(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)
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)。
关键词
茶园
林地
氮素转化模型
氮转化速率
NO_(3)^(-)保持
tea plantation
forest land
nitrogen transformation model
nitrogen transformation rate
NO_(3)^(-)retention
