节灌控排条件下稻田氮平衡模拟及利用效率分析

运用DNDC模型模拟分析不同节灌、施肥、控排条件下稻田氮素平衡状况及氮肥利用效率。结果表明,节水灌溉控制排水条件下,施氮量不大于180kg/hm2时,稻田土壤氮库均呈现亏损,亏损量为54.7～127.6kg/hm2,亏损量随着施氮量的增加而逐渐减小;除浅灌深蓄中氮和浅灌深蓄高氮处理外,控制排水处理土壤氮素亏损量均大于常规排水;浅灌深蓄、施中氮和控制排水的组合是最佳的水肥处理模式。

Simulated Nitrogen Balance and Nitrogen Use Efficiency in Paddy Rice under Water-saving Irrigation and Controlled Drainage

The nitrogen balance and nitrogen use efficiency under different conditions of irrigation methods,fertilization levels,controlled drainage were analyzed by DNDC mode1.The result showed that the soil nitrogen pool was in loss under all modes,and its amount ranged from 54.7 to 127.6 kg/hm2,which decreased slowly with the increasing nitrogen fertilization consumption.Except for the G1F1 and G1F2 modes,nitrogen loss in soils under controlled drainage mode was greater than conventional drainage mode.The combination of shallow irrigation and deep reservoir,medium level of nitrogen consumption and controlled drainage was proved to be the best water and fertilizer mode.