摘要
在北京潮土上研究了冬小麦夏玉米轮作体系下土壤硝化反硝化作用以及N2O排放情况。结果表明,小麦生育期土壤温度及含水量较低,无论是反硝化损失氮量还是土壤的N2O生成排放量均不高。土壤的N2O生成排放量与反硝化氮量相当或低于反硝化氮量。玉米生育期土壤温度升高以及孔隙含水量有较大的改善,反硝化损失氮量、N2O生成排放量有明显上升。通常情况下土壤反硝化损失氮量与N2O排放氮量基本处于同一水平。在玉米十叶期追肥后的较短时间内,N2O总排放量明显高于反硝化损失氮量,说明至少在这一阶段中,硝化作用在北方旱地土壤N2O的排放中发挥了主要作用。在评价北方旱地农田土壤氮素硝化反硝化损失中,硝化作用的氮素损失是不可忽视的重要方面。
Nitrification-denitrification and N2O prodution/emission from a fluvial soil were studied in wheat-maize rotation croppingsystem. The results showed that either denitrification-N loss or N2O endssion were quite low in wheat growth season due to lowersoil temperature and water content, and N2O-N production rate was almost comparable to denitrification or slightly lower than thelater.In maize season both denitrification-N and N2O emission increased significantly,and the dynamic of N2O-N production anddenitrification was quite simile. After fertilizer nitrogen topdressing at the maize tenth leaf stage N2O emission rate was greatlyhigher than denitrification rate demonstrating that nitrification was mainly responsible for N2O production at least at this stage.Thereafter nitrogen loss by nitrification should not be neglected in evaluation of gaseous nitrogen loss.
出处
《土壤与环境》
CSCD
2001年第4期273-277,共5页
Soil and Environmental Sciences
基金
北京市科学基金重大项目(6980001)
北京市科技新星项目(954813300)
关键词
潮土
玉米
硝化
反硝化
N2O
农田土壤
fluvial soil
wheat
maize
nitrification, denitrification
N2O
