不同灌溉方式下木薯根区水分空间分布及耗水动态变化研究

A Study of the Soil Water Spatial Distribution in Root Zones and the Dynamic Change in the Water Consumption of Cassava under Different Irrigation Methods

设置滴灌、小管出流、微喷灌3种灌溉方式,研究不同灌溉方式下木薯根区土壤水分空间分布及其耗水变化规律。结果发现:(1)滴灌灌水集中,土壤水分在根区剖面以根际为中心对称分布;小管出流水分沿支管出口方向入渗,形成斜向下迁移的态势;微喷灌喷洒均匀,根区各层次土壤含水量差异不大。(2)滴灌能有效抑制木薯棵间蒸发,降低水分消耗,提高块根产量,其水分利用效率显著高于其他处理;微喷灌湿润面大,棵间蒸发量较高,其产量和水分利用效率较低;小管出流土壤水分散失量最高,其产量和水分利用效率最低。综上所述,滴灌对木薯的节水增产效应最优。

Three irrigation methods of drip irrigation, small pipe outflow, micro - sprinkler irrigation are designed to study the soil water spatial distribution in root zones and changing regularity of water consumption of cassava. The results show that ： （1）Drip irrigation centralizes water in root zone profile, and the soil moisture is distributed symmetrically around the rhizosphere. The water of small pipe outflow percolates along the direction of branch outlet, then the trend of inclined downward migration is formed. Micro - sprinkler irrigation sprayed evenly, and the difference of soil moisture content at each level of root zone is not significant. （2）Drip irrigation can effectively inhibit evaporation of cassava, reduce water consumption, improve tuber yield, and its water use efficiency is significantly higher than other treatments. The wetted surface of micro-sprinkler irrigation is larger, and the soil evaporation is higher, so its yield and water use efliciency is lower than drip irrigation. The soil water evaporation of small pipe outflow is the highest, and its yield and water use efficiency are the lowest. From the above, the water-saving and production-increase effect of drip irrigation on cassava is the best.