棉田暗管控制排水和氮素流失研究

Drainage and Nitrogen Loss from Controlled Pipe Drainage Cotton Field

在湖北荆州丫角排灌试验站进行暗管控制排水和自由排水对照试验,结果发现,暗管排水累积排水量随时间呈线性变化;暗管排水氮素累积流失量随时间呈二次曲线变化。控制水位为30 cm的田块氮素累积流失量随时间而增加,而其他控制排水及自由排水田块氮素累积流失量随时间而减少。控制排水可以减少累积排水量和氮素累积流失量,且随控制水位增加排水量和氮素累积流失量减少。控制水位过高不利于减少氮素流失。

A field contrastive experiment was set up at drainage and irrigation experimental station,Jingzhou Yajiao,Hubei.Results showed that controlled drainage reduced drain outflow and nitrogen loss.Drain outflow and nitrogen loss declined with increment of the controlled water table.There was a positive linear relationship between drain outflow and time.Accumulation of nitrogen loss from pipe drainage fluctuated with time fitted a conic curve and the related coefficient was up to 0.95.The increment of drain outflow accumulation from controlled drainage of 30 cm increased with time and from other controlled treatments and free drainage treatment decreased with time.Controlled water table would too high to reduce nitrogen loss.