摘要
在室内培养条件下,以硝酸钙和碳酸氢铵为供试肥料,在45%、65%、100%田间持水量(Field Capacity-FC)条件下,研究了硝态氮肥和铵态氮肥在陕西关中塿土中对N2O释放的影响并区分了N2O产生的途径。结果表明,45%FC和65%FC条件下,施用铵态氮肥土壤的N2O释放量大于硝态氮肥,100%FC下反之。但当土壤湿度达到田间持水量时,由于硝化和反硝化作用都很强烈,两种肥料处理的N2O排放均达到最大值,分别为3.20,2.94mgkg-1。在10天培养期内,碳铵处理在各水分条件下释放的N2O总量接近,分别为2.05、2.03、2.94mgkg-1干土,而硝酸钙处理在各水分条件下释放的N2O总量分别为1.53、1.75、3.20mgkg-1干土。但通过硝化反硝化途径产生的N2O量对N2O总释放量的贡献差异较大。45%FC时,碳铵处理硝化和反硝化作用对N2O排放的贡献率分别为84.77%和15.23%;65%FC时分别为71.78%和28.22%;100%FC时的为48.50%和51.50%。由此可见,在本试验期内,硝化作用是土壤N2O排放的主要来源。硝酸钙在土壤中由于不存在硝化作用,所产生的N2O全部来自反硝化过程,在45%FC、65%FC和100%FC条件下,N2O释放量随含水量增加而增加,分别为1.53,1.75和3.20mgkg-1干土。
To study the effects of nitrate and ammonium fertilizers on N2O emission, an incubation experiment was conducted in laboratory with Ca （NO3）2 and NH4HCO3 under 45%, 65%, 100% field capacity （FC） in Anthrosol of Guanzhong, Shanxi Province. The results indicated that the emission amount of N2O in soil applied ammonium fertilizer was greater than that of applied nitrate fertilizer under 45% and 65% FC. However, N2O flux got to peak in these two N-fertilizer treatments when soil moisture was 100% FC. During the incubation of 10 days, there was no significant difference among the total amount of N2O emission under different soil moisture levels in NH4HCO3 treatment. But there was great difference of N2O emission from nitrification and denitrification. Under 45%FC, the contribution of N2O emission from nitrification and denitrification in NH4HCO3 treatment were 84.77% and 15.23%, respectively, and 71.78% and 28.22% for 65% FC, 48.50% and 51.50% for 100% FC, which indicated that nitrification was the main source of N2O emission in this experiment.
出处
《土壤通报》
CAS
CSCD
北大核心
2009年第2期325-330,共6页
Chinese Journal of Soil Science
基金
国家自然科学基金资助项目(30370822)
黄土高原土壤侵蚀与旱地农业国家重点实验室基金课题(10501-139)资助
