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用田间原位土壤探头测定法和乙炔抑制未扰动土柱法 ,对黄土性土壤N2 O的排放进行了研究。试验结果表明 ,黄土性土壤N2 O的排放量存在着明显的季节和空间变异。季节变化与田间水分因子密切相关 ,N2 O高峰常出现在灌水 (降水 ) 3天后 ,施肥处理和对照的趋势完全一致。全年中八月份各土层N2 O浓度最高 ;在最高峰值时 ,施肥处理的N2 O浓度几乎是对照处理的 2 .5倍。土壤剖面中N2 O的浓度的顺序是 1 0cm <30cm <1 50cm <90cm <60cm ,以 60～90cm土层最高。影响黄土性土壤反硝化的主要因子是作为微生物能源和碳源的有机物质 ,在碳源充足时 ,土壤的硝态氮含量和水分因子是限制因子。
Field soil in situ probe method and acetylene inhibition unperturbed soil column method, loess soil N2 O emissions were studied. The results show that there is obvious seasonal and spatial variation of N2 O emission in loess soil. Seasonal changes are closely related to field moisture factors. Peaks of N2 O often occur three days after irrigation (precipitation), and the trends of fertilization and control are exactly the same. The highest concentration of N 2 O was observed in all soil layers in August. At the highest peak, the N 2 O concentration of fertilization treatments was almost 2.5 times that of the control treatment. The order of the concentration of N2 O in the soil profile is 10 cm <30 cm <1 50 cm <90 cm <60 cm, and the highest in 60-90 cm soil layer. The main factors influencing the denitrification of loess soil are organic substances that are microbial energy and carbon source. When the carbon source is sufficient, the nitrate nitrogen content and water factor of soil are the limiting factors.