苹果树蒸发蒸腾量的测定和计算

Measuring and Estimating Evapotranspiration of an Apple (Malus pumila Mill.) Orchard

采用热脉冲技术 -微型蒸渗仪和水量平衡原理 ,测定和计算了树体大小不均匀的苹果树蒸发蒸腾及其组成 ,利用冠层分析仪测定了叶面积指数动态变化。两种不同的方法测定和计算的蒸发蒸腾量之间的偏差很小 ,最大偏差不超过 10 %。在夏季 ,蒸发蒸腾主要由果树蒸腾组成 ,而在春季和秋季 ,刚好相反。作物系数 (Kc)和叶面积指数成线性关系 。

Soil water balance and sap flow plus mini-lysimeter methods were used to measure evapotranspiration and its components within an uneven-sized apple orchard for 2 years.The green leaf area index (LAI) increment was also measured. There were quantitative similarities between soil water balance estimates and sap flow plus mini-lysimeter measurements, with differences usually less than 10%. During the dry summer, the soil evaporation component of ET falls to very small values and the evapotranspiration of the orchard was mainly composed of the tree transpiration. In the spring and autumn, there is a contrary phenomenon. There was a linear relationship between crop coefficient (Kc) and LAI, suggesting that we can predict the crop coefficient (Kc) and estimate the ET based on the common meteorology data in the region.