Nitrous Oxide Evolution from Agricultural Soil: A Regression Approach

N_2O emission from soil is affected by many factors. In this study, N_2O flux, soil temperature, water content, NO_3^- and NH_4^+ concentrations were simultaneously measured in winter wheat field. N_2O flux, NO_3^- and NH_4^+ concentrations were all lognormally distributed, while water content was normally distributed. The relationship between N_2O flux and soil factors was also studied. N_2O flux was most highly correlated with soil temperature. Regression model was developed to explain the variability of N_2O emission from agricultural soil using multifactorial analysis.

不同生境下氮沉降对土壤N_(2)O通量影响的整合分析

基于在我国开展的66个野外氮沉降模拟试验的290组数据,采用整合分析方法,探究实验样地特征(气候因子、土壤性质)和施氮因素对施氮后土壤N_(2)O通量变化的影响。结果表明:样地的年均降水量、年均温、自然氮沉降量和土壤C/N与施氮后N_(2)O通量增幅呈显著正相关,土壤pH与施氮后N_(2)O通量增幅呈显著负相关。湿地生态系统土壤对施氮最敏感,森林生态系统次之,草原生态系统最小。所有的样地因子中,土壤pH和C/N对施氮后N_(2)O通量变化幅度的影响最大。施加硝态氮后土壤N_(2)O通量增幅最大,施加尿素与铵态氮后N_(2)O通量增幅相当,而施加硝酸铵后N_(2)O通量增幅最小。综上,在准确评估和预测土壤N_(2)O通量对氮沉降的响应时,应综合考虑样地特征及氮源种类的影响。