土壤水分状况及环境条件对水稻蒸腾的影响

在南方红壤区用田间测坑试验，研究了高、中、低3种土壤水分条件下的早、晚稻蒸腾速率和水分利用效率的变化，蒸腾日变化结果表明，蒸腾速率受许多田间小气候因子的影响，相关分析及多元逐步回归分析表明，叶片与空气相对湿度差和叶面温度对水稻叶片蒸腾影响最大，处理B（中等土壤水分条件）可以明显提高叶片水利用率和产是，处理C提高了叶片水分利用效率，却导致晚稻减产，早稻中、低土壤水分条件可以减小叶片蒸腾速率，而晚稻上并不能明显减少叶片蒸腾。

Effects of soil watercondition and microelimate on transpiration rate of rice

The transpiration rate and water use efficiency (WUE) of rice were studied under high,moderate and low soil water conditions (treatments A,B and C) in the red soil area of southern China. Diurnal variation of transpiration showed that rice transpiration rate was influenced by several microclimatic factors in the field.Correlation analysis and stepping multi regression analysis suggested that the difference of relative humidity between leaf and air,and the leaf temperature were the two main factors affecting the transpiration rate of rice.The results also showed that WUE was and yield were increased significantly in treatment B.While in treatment C,the WUE increased,but the yield of late rice decreased.The transpiration rate of early rice was decreased under moderate and low soil water treatments,but this did not happen to late rice.