黄土丘陵枣林非生育期土壤水分 损失及其剖面气态水分析

针对黄土丘陵半干旱区枣林地土壤干化缺水严重的现象,利用2012—2015年土壤水分、温度等实测数据,分析枣林土壤水分损失的运动规律及其机理。结果表明:休眠期是枣林地土壤水分损失十分严重的阶段,0—200cm土层土壤水分损失量达到85.64~92.34mm,大约是同期降雨量的2倍。蒸发是休眠期土壤水分损失的主体。在垂直剖面上,休眠期土壤水分损失自上而下呈现减少趋势,土壤水分由地下向上运移,最终在近地表以气态水形式散失到大气。土壤气态水运动的活跃层在0—11cm土层间,最大深度为540cm。受温度、相对湿度等因素的影响,土壤气态水通量随土壤深度增加而减少。

Mechanism of soil water loss in non-growth period of jujube plantation in the loess hilly region

SBased on the soil desiccation and water shortageSproblems inSthe semi-arid Loess Plateau in China, the soil water and temperature ofS0-1000Scm soil layers in a dense jujube plantation was measured duringS2012 to 2015 in order to investigate the mechanism of soil water loss in jujube plantations in the region.SThe results of our analysis showed thatSevaporation is the main reason of the soil water loss in non-growth period: the soil water moved toward the upper soil layer and eventually converted to water vapor when near the soil surface, then diffused into the atmosphere. The soil water loss in the non-growth period is serious: the amount of soil water loss in 0-200 cm soil layerSwasSup to 85.64-92.34 mm, which is about twice as much as contemporaneous rainfall. BothSthe water loss amount and the net flux of soil water vapordecreased with the increase of soil depths in the 0-540 cm soil profile. The most active layer of soil water loss is 0-11 cm.