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利用土壤探头法和密闭气室法相结合 ,就黄土高原旱地土壤玉米生长期灌溉和降水对N2 O气态损失的影响进行了研究 ;并采用乙炔抑制原状土柱培养法 ,对土壤由湿变干和由干变湿过程中N2 O变化进行了模拟。试验结果表明 ,在旱地土壤上 ,N2 O的变化一般较小 ,但在降雨或者灌溉后无论是土壤N2 O通量或者土壤剖面中N2 O的浓度均呈现上升趋势 ,且这种变化趋势与同时期降雨量的变化趋势相同。培养结果说明 ,在相同的土壤孔隙水含量 (WFPS)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 ;在土壤由干变湿过程中N2 O通量随土壤WFPS含量的增加而上升 ,但在土壤由湿变干过程中土壤N2 O通量在WFPS含量为 70 %时达到最大 ,而后随土壤WFPS含量的减少而下降。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
Using the combination of soil probe method and closed-cell method, the effects of irrigation and precipitation on the gas loss of N2 O in the maize growing season in the dry land of the Loess Plateau were studied. By using the method of inhibiting soil column cultivation with acetylene, It is simulated by the change of N2 O during dry-to-wet process. The results showed that the variation of N 2 O was generally small in upland soil, but both the N 2 O flux in the soil and the concentration of N 2 O in the soil profile showed an upward trend after rainfall or irrigation, The trend of period rainfall is the same. The results of culture showed that under the same soil water content (WFPS), the flux of N2 O generated by the wet-drying process was higher than that of the soil during dry-wetting process. When the soil was changed from dry to wet process The fluxes of N2 O increased with the increase of soil WFPS content, but reached the maximum at the WFPS content of 70% when the soil was wet-dried, and then decreased with the decrease of soil WFPS content. Compared with the control, the change trend of fertilization and control was the same, but the change range of non-fertilization treatment was smaller