摘要
用密闭气室法对黄土高原旱地土壤灌溉后 N2 O气态损失进行了研究 ,并采用乙炔抑制的原状土柱实验室培养法 ,对土壤由湿变干和由干变湿过程中 N2 O通量的变化进行了模拟。试验结果表明 :在旱地土壤上 ,N2 O通量的变化一般较小 ,但在灌溉后其呈现上升的趋势 ,且这种变化在灌溉后 2 d～ 3d出现 ;整个测定过程中密闭气室法测得对照和施肥处理 N2 O通量分别为 6 .79μg/ (h· m2 )和 15 .6 4μg/ (h· m2 )。培养实验的结果表明 :同一土壤在同等的土壤 WFPS含量条件下 ,土壤由湿变干过程产生的 N2 O通量高于土壤由干变湿过程中的产生量 ;施肥处理与对照相比两者的变化趋势相同 ,但不施肥处理的变化幅度较小。
By using closed chamber methods, field experiments were carried out in the semiarid area of dryland to study the effects of irrigation and rainfall on the N 2O loss. Meanwhile intact C 2H 2 inhibition soil cores incubation test were performed in the lab to study influences of wetting and drying cycle on the N 2O emission so that to further explain the field results. The results show that N 2O emission in the dryland is usually low but it increases rapidly after irrigating the land or rainfall, the trend N 2O flux changes with the time are similar to that of temporal rainfall pattern. N 2O flux for the fertilized plot and nonfertilized plot were 12.14 μg/(h·m 2) and 5.02 μg/(h·m 2) before irrigation, and those were 21.814 μg/(h·m 2) and 8.214 μg/(h·m 2) after irrigation, respectively. Incubation test shows that for the wetting to drying cycle the highest N 2O flux takes place at the soil WFPS 70%. After that N 2O flux would dramatically reduce with the decreasing of the soil WFPS content. For the drying to wetting cycle, soil N 2O emission flux increases with the soil WFPS content increases. However, when soils have same WFPS content, the influence of soil from wetting to drying cycle on N 2O flux is bigger than that from drying to wetting. The control plot has the same tread as the fertilized plot but the curve is much more flatter than applied N treatment.
出处
《干旱地区农业研究》
CSCD
北大核心
2002年第2期28-31,48,共5页
Agricultural Research in the Arid Areas
基金
中国与瑞典国际合作项目资助
农业部重点科研计划项目 (95农 -0 3 -0 1-0 3 )
西北农林科技大学重点科研项目资助
