双层暗管排灌水与燕麦移盐对土壤水盐影响的协同机制研究

我国盐碱地资源丰富，改良提高盐碱土地质量是一项重要国家战略。燕麦具有积累、移除土壤盐分的功能，被认为是盐碱地修复植物。然而燕麦在环渤海地下水埋深浅的地区，极易受到早春土壤返浆产生的涝渍害和春末夏初干旱形成的旱-盐双重胁迫的威胁，严重影响其修复盐碱地的效果。双层暗管具有排水抑制土壤盐分和灌溉淋洗土壤盐分的双重作用。针对上述问题，本项目拟使用暗管降低地下水位减少春季涝渍害和抑制返盐。在春末夏初利用上层密布暗管进行咸水灌溉补充土壤水分，淋洗土壤盐分。使燕麦获得适宜的水盐环境，从而到达燕麦和暗管协同修复盐碱地和燕麦生产的双重目的。项目拟通过暗管排水控制地下水埋深和暗管地下灌溉处理，研究其对土壤水盐运移变化过程的影响。同时研究燕麦种植对土壤盐分和水分的适应机制与响应。最终探明暗管排、灌水与燕麦种植相结合对土壤水盐运移过程的协同作用机制，为该区域生态工程与植物修复协同改良盐碱地提供理论指导和数据支撑。

It is an important strategy for China that improving the saline alkali land to improve food production, because amount of farm land was used to building construction. Oat as phytoremediation can uptake and remove salt from soil. But it is limited by waterlogging in early spring and drought damage in early summer. Using subsurface drainage can drainage and irrigate, which seems to solve these oat plant problems. This study aims to use subsurface drainage to reduce the groundwater table, so that decline the salt up to the root zone. And irrigating with the up layer subsurface drainage can increase soil moisture when the drought stress came. So that it enhances the oat planting as phytoremediation to remove salt ions from soil. The project proposed was (1) to study the changes of soil salt and moisture after controlling at different depth of groundwater tables in waterlogging stage and irrigated by up layer subsurface drainage at drought stress stages, (2) the adaptation mechanism and response of different oat planting density on soil water and salt controlled by subsurface, (3) the interaction in soil salt content and moisture of subsurface drainage or irrigation plus the oat phytoremediation. This study will provide a theoretical guidance for salt land in Bohai sea area.