保水剂浅层施用对土壤减蒸抑盐的影响及其机理

Yellow River irrigation area of Northwest with less rainfall, much evaporation is the important base of grain production in China. Long-term flooding irrigation has resulted in large scale soil secondary salinization. Water shortage will be aggravated because of deceasing total amount of water taken from Yellow River strictly allocated by state and inceasing water requirment for social development. How to effectively improve the soil water holding capacity, reduce soil evaporation, inhibition of salt accumulation and improving crop yield is an important issue of solving water-saving bottleneck in salinization irrigation districts. The experiment will be conducted to investigate super-absorbents(SAP) application in Yellow River irrigation area in Northwest (i) the effects of SAPs mixed with soils in upper layer on soil physico-chemical properties,water evaporation, salinity transfer and accumulation in applied layers (ii) The impact of soil physico-chemical properties in SAPs application layer on the hydraulic properties of no applied soils layers (iii) The effects of physico-chemical properties change in applied layers on soil evaporation and salt movement in whole soil layers under different SAPs application methods.The aim in the study is to abtain a relationship in soil physical and chemical properties between application layer and no application layer of SAPs when mixed with soils in upper layer and to reveal the mechanisms for soil water movement and salt accumulation.The results can be used for guide to SAPs appliaction to reduce evaporation and salt,increasing water use efficiency in northwest irrigation areas.

西北引黄灌区是我国重要的粮食生产基地，但降雨少，蒸发量大，土壤次生盐碱化严重。近年来沿黄地区对水需求不断增长以及国家实行最严格水资源管理制度，农业用水量面临不断缩减，如何有效提高土壤持水能力、减少土壤蒸发、抑制盐分累积、提高作物产量，成为解决西北盐碱化灌区农业田间节水关键技术的一项重要课题。 本项目拟开展保水剂浅层施用对土壤减蒸抑盐影响的研究：1）保水剂浅层施用对施用层土壤理化性质、水分蒸发、盐分迁移与累积的影响；２）保水剂施用层土壤理化性质变化对非施用层的水力特性的影响；3）保水剂不同浅层施用参数下，施用层土壤理化性质变化对整个土体（施用与非施用层）水分蒸发与盐分迁移的影响。 得出保水剂浅层施用对施用层以及非施用层土壤理化性质的影响量化关系。揭示保水剂浅层调控对土壤水分运动、土体盐分迁移和表层积累的影响机理。为引黄灌区利用保水剂减蒸抑盐、提高水分利用效率提供理论依据。

)：西北引黄灌区是我国重要的粮食生产基地，但降雨少，蒸发量大，土壤次生盐.碱化严重。近年来沿黄地区对水需求不断增长以及国家实行最严格水资源管理制度，农业用.水量面临不断缩减，如何有效提高土壤持水能力、减少土壤蒸发、抑制盐分累积、提高作物.产量，成为解决西北盐碱化灌区农业田间节水关键技术的一项重要课题。.本项目拟开展保水剂浅层施用对土壤减蒸抑盐影响的研究：1）保水剂浅层施用对施用层土.壤理化性质、水分蒸发、盐分迁移与累积的影响；２）保水剂施用层土壤理化性质变化对非.施用层的水力特性的影响；3）保水剂不同浅层施用参数下，施用层土壤理化性质变化对整.个土体（施用与非施用层）水分蒸发与盐分迁移的影响。.得出保水剂浅层施用对施用层以及非施用层土壤理化性质的影响量化关系。揭示保水剂浅层.调控对土壤水分运动、土体盐分迁移和表层积累的影响机理。为引黄灌区利用保水剂减蒸抑.盐、提高水分利用效率提供理论依据。