地下水埋深对夏玉米根冠生长和耗水量的影响

Effects of Different Groundwater Depths on Root and Shoot growth and Water Consumption of Summer Maize

利用排水式蒸渗仪,借助自制的Mariotte瓶装置,通过设置6种地下水埋深控制处理(地下水位埋深分别为0.2、0.4、0.6、0.8、1.01、.2m),探讨了不同地下水埋深对夏玉米的地上部分、根系生物量及耗水量的影响。结果表明,夏玉米株高和冠层叶面积随地下水埋深减小有增加的趋势,但是当地下水埋深减小到一定程度时就会抑制株高、叶面积,地下水埋深0.6m处理株高和叶面积系数(LAI)最大。各土层根系及其总生物量随地下水埋深增大而增大;地上部总生物量与地下部根生物量的比值随地下水埋深的增大呈明显减少的趋势。夏玉米全生育期和各阶段耗水量分别与地下水埋深呈较好的负相关关系,达到极显著水平(P<0.01);地下水补给量占耗水量的比例随地下水埋深的增大而逐步降低。研究结果可为江淮丘陵区夏玉米灌溉制度的制定及农田排水工程的设计提供参考依据。

Through setting 6 treatments with groundwater depth of 0.2 m（T1）, 0.4 m（T2）, 0.6 m（T3）, 0.8 m（T4）, 1.0 m（TS） and 1.2 m（T6）, the root and shoot growth, and water consumption of summer maize were investigated under different groundwater depths controlled by Mariotte bottle devices in drain- able lysimeters. Results showed that plant height and leaf area increased with the decreasing of the groundwater depth, while the groundwater depth lowered to a certain extent, the shoot growth of Maize would be inhibited. Plant height and LAI （Leaf area index） of T3 treatment reached the maximum. Root biomass in each soil layers and the whole soil layers increased with the increasing of groundwater depth. The ratio of total shoot to root biomass showed a decreasing trend significantly as the groundwater depth increasing. There were a good negative correlation between water consumption and groundwater depth at each growth stage or whole growth period, which the regression equation achieved a significant level （P〈0.01）. The proportion of groundwater recharge accounting for water consumption gradually decreased with the groundwater depth increasing. This result provide a reference to develop irrigation system and to design field drainage engineering of summer maize in Jianghuai areas.