晚稻蒸腾速率及其影响因素试验研究

根据国家“863”节水农业重大专项“江西示范区晚稻控制灌溉”试验资料,分析了水稻蒸腾速率日变化、全生育期变化的规律以及不同生育阶段蒸腾速率与环境因子、气孔导度和土壤水分状况的相互关系。研究结果表明,田间土壤含水率的降低推延了蒸腾速率日最大值的出现;常灌处理水稻蒸腾速率一般高于控灌处理,但控灌午后的蒸腾速率等于或高于常灌;空气温度、叶面温度、饱和水汽压差和气孔导度是影响水稻的蒸腾速率的关键因素,并在水稻不同生育阶段表现不同的影响程度;气孔导度与晚稻蒸腾速率具有一定相关性;蒸腾速率受土壤含水率变化的影响,且在恢复供水后,蒸腾速率出现一定的反弹现象并表现出不同程度的滞后性。

Experimentation of Transpiration Rate and Influence Factors of Late Rice

Based on the experimentation of controlled irrigation on late rice, the national "863" special project on water-saving irrigation, performed at Jiangxi province, diurnal change and variation in the whole growing season of transpiration rate were analyzed in this paper. In addition, relationships between transpiration and meteorological factors, stoma conductance, soil water moisture were studied. Results showed that the maximum of diurnal transpiration would be delayed when soil water moisture decreased. Transpiration rates in traditional irrigation usually were higher than that in controlled irrigation, but sometimes were lower or equal in the afternoon. Air temperature, leaf temperature, vapor pressure deficit and stoma conductance were the key factors affecting transpiration, and the effects would be different in different growing stages. Correlation existed between stoma conductance and transpiration rate. The transpiration rate were also affected by soil water moisture and rebound after recovering water, but such effects would be lagged in different degrees.