红壤坡地不同土地利用方式土壤蒸发和植被蒸腾规律研究

Rules of soil evaporation and plant transpiration under different land use patterns in the sloping land of red soil

摘要: 为明确红壤坡地土壤水分耗散特征，通过田间定位观测，分析了农作区、茶园和柑园土壤水分蒸发和蒸腾过程。结果表明：蒸发、蒸腾与土壤表层含水率和植被叶面积指数关系密切，不同利用方式日蒸发量大小顺序为遮荫茶园<对照茶园<柑园<农作区。茶树和柑蒸腾速率日变化曲线均呈现单峰型，柑日蒸腾速率比对照茶树弱，这两种土地利用方式下6-10月均以蒸腾耗水为主。遮荫可有效削弱茶园土壤蒸发及植被蒸腾。茶园蒸发受微地形条件影响较大，梯地蒸发比梯坎蒸发弱，而农作区和柑园土壤蒸发更多受水分条件的影响。合理的土地利用方式和适度遮荫可以有效降低红壤坡地土壤水分散失，提高水分利用效率和防治季节性干旱。

Abstract: Aims to understand the characteristics of soil water budget in a sloping land of red soil, using in-situ measurements, soil evaporation and plant transpiration in the farmland, tea garden and orange orchard were analyzed. Results show that soil surface water content and leaf area index(LAI) play a critical role in soil evaporation and plant transpiration. Soil evaporation is ordered as follows: shaded tea plot