地下水埋深对春玉米需水量及需水系数的影响

采用排水式蒸渗仪试验,研究了不同地下水埋深时,春玉米需水量和地下水利用量的变化规律,对春玉米需水系数进行了计算。结果表明,在全生育期内,春玉米需水量最大值出现在地下水埋深为0.5 m时,1.0 m时最小;地下水埋深对春玉米需水量的阶段分配没有太大影响,不同地下水埋深处理的规律基本一致,即拔节到抽穗期最小,灌浆到收获期最大;不同地下水埋深的春玉米日需水量变化规律也基本一致,即前期较小,生长盛期达到最大;春玉米需水系数在播种-拔节期最小,在抽穗-灌浆期最大。研究结果可为春玉米节水灌溉制度的制定和高效灌溉管理提供参考。

Influence of Groundwater Depth on Evapotranspiration and Water Requirement Coefficient of Spring Maize

Water requirement of spring maize and groundwater contribution were investigated under different groundwater depth by using drainable lysimeter.Water requirement coefficients were analyzed later.Results showed that the water requirement of spring maize in whole growth period reached maximum when the groundwater depth was 0.5 m,and its minimum appeared while the groundwater depth was 1.0 m.It is little influence on distribution of water requirement in each growth stage that showed consistent under different groundwater depth.The dynamic changes of daily evapotranspiration of spring maize at the different groundwater depth were consistent basically,namely the value would be low in early growth period,and reach maximum at prime period.Water requirement coefficients reach minimum between seedling and jointing period and maximum between heading and grain-filling period.Results obtained from the paper would be helpful to the study of water-saving irrigation design and effective irrigation management of spring maize.