大型蒸渗仪与小型棵间蒸发器结合测定冬小麦蒸散的研究

Determination of daily evaporation and evapotranspiration of winter wheat field by large scale weighing lysimeter and micro lysimeter

本文利用大型称重式蒸渗仪和棵间蒸发器仔细研究了冬小麦生长期间的逐日蒸散和蒸发过程，确定了冬小麦生长期间棵间蒸发占总蒸散量的２９７５％；棵间蒸发占蒸散的比例随生育时期叶面积指数（ＬＡＩ）和表层土壤含水量的变化而变化．同时确定了冬小麦生长期间的作物系数Ｋｃ．

The large scale weighing lysimeter and micro lysimeter are employed to determine the daily alteration processes of evapotranspiration and soil evaporation of winter wheat in its growth stages. According to the observation data, the authors found that about 30% of the total field evapotranspiration is consumed by the soil evaporation under canopy. Furthermore, the water saving farming can be expressed as increasing leaf area index (LAI) in the early stage of growth and controlling topsoil moisture under the canopy. Based on the evapotranspiration determination the dimensionless crop coefficient can be calculated.