| 交替灌溉条件下水氮耦合对土壤气态氮排放的影响 |
| 摘要点击 1884 全文点击 1947 投稿时间：2010-06-21 修订日期：2010-09-08 |
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| 中文关键词 水氮耦合 交替灌溉 氨挥发 氧化亚氮排放 |
| 英文关键词 coupling of water and N alternate irrigation and N placement NH3 volatilization soil N2O emission |
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| 中文摘要 |
| 通过大田试验，以密闭法与硼酸吸收法收集和测定土壤NH3挥发量，以密闭法收集和气相色谱法测定土壤N2O释放量.采用二元二次正交旋转组合设计，研究交替灌溉施肥条件下的水氮数量耦合对NH3挥发，N2O排放及夏玉米产量的影响，并建立相应的数学模型.交替灌溉施肥处理NH3-N挥发量为4.78～17.00 kg/hm2，氨挥发引起的氮肥损失率为1.89%～11.89%；N2O-N排放量为0.59～0.88 kg/hm2，氮肥损失率为 0.01%～0.31%；常规处理NH3-N和N2O-N排放量分别为19.55 kg/hm2和1.29 kg/hm2，其氮肥损失率分别为8.27%和0.45%.交替灌溉施肥处理的籽粒产量为4163.18～6942.00 kg/hm2.模拟结果表明，气态氮（NH3-N+ N2O-N）最低释放量为9.28 kg/hm2，相应水氮配比为800.00 m3/hm2（灌水量）和24.80 kg/hm2（施氮量）.最高籽粒产量为6367.07 kg/hm2，相应水氮配比为930.12 m3/hm2（灌水量）和238.19 kg/hm2（施氮量）.气态氮释放量≤12.84 kg/hm2的管理方案：灌水量658.06～941.94 m3/hm2，施氮量87.36～131.16 kg/hm2.籽粒产量≥4934.91 kg/hm2的管理方案：灌水量910.22～1134.20 m3/hm2，施氮量215.89～270.78 kg/hm2.控制性交替灌溉施肥条件下，气态氮损失较低和产量较高的灌水量范围为910.22～941.94 m3/hm2，氮肥用量则无交集.与常规灌溉施肥相比，水肥异区交替灌溉施肥显著降低气态氮释放，增加产量. |
| 英文摘要 |
| A field experiment was conducted by second-order central designed with composite orthogonal rotational matrix for two variables to investigate the effects of quantity coupling between water and N under AINP (alternate irrigation and N Placement) on soil NH3 volatilization and N2O emission and summer maize yield. The gaseous N was collected by open-bottomed chambers made from PVC in field. NH3 was absorbed in the chamber with boric acid and then titrated with dilution H2SO4 in the lab. A 5mL sample of headspace air was taken at 2-4 d interval after fertilization and stored in evacuated glass vials with butyl rubber seals which were put in 4℃ fridge until analysis. The N2O concentration of each sample was measured by Varian 3800 gas chromatograph. The results indicated that total NH3-N volatilization accumulation of AINP were 4.78-17.00 kg/hm2, and 1.89%-11.89% of applied N, while soil N2O-N emission were 0.59-0.88 kg/hm2 , and 0.01%-0.31% of applied N. Total NH3-N volatilization and N2O-N emission from conventional treatment were 19.55 kg/hm2 and 1.29 kg/hm2, and 8.27% and 0.45% of applied N respectively. Maize yield of AINP were 4163.18-6942.00 kg/hm2. The simulation results showed that the lowest of total NH3-N volatilization and N2O-N emission would be 9.28 kg/hm2 when water amount was 800.00 m3/hm2 and N rate was 24.80 kg/hm2. The highest maize yield would be 6367.07 kg/hm2 when optimal water amount and N ratio were 930.12 m3/hm2 and 238.19 kg/hm2 respectively. The NH3 volatilization and N2O emission could be lower (≤12.84 kg/hm2 ) when irrigation water were 658.06-941.94 m3/hm2 and N rate were 87.36-131.16 kg/hm2. The maize yield could be higher (≥4934.91 kg/hm2) when the water amount were 910.22-1134.20 m3/hm2 and N rate were 215.89-270.78 kg/hm2. Under AINP, there could be not only lower the gaseous N loss but also higher yield when the optimal irrigation water were 910.22-941.94 m3/hm2, but there was no agreement of the N rate between higher yield treat and the lower N loss one. Compared with conventional irrigation and N application, AINP could decrease NH3 volatilization and N2O emission and increase summer maize yield significantly. |
