南方现代化温室黄瓜夏季蒸腾研究

Cucumber Canopy Transpiration in Subtropical Modern Greenhouse Under Summer Climate Condition

温室作物蒸腾不仅直接影响到温室内空气温湿度 ,而且是现代温室中确定合理的作物肥水灌溉控制目标的主要依据。研究采用Penman Monteith方程模拟南方现代化温室黄瓜在夏季高温高湿条件下的蒸腾速率 ,并通过冠层微气候和蒸腾速率观测 ,分析了影响蒸腾的主要温室环境因素。结果表明 ,Penman Monteith方程模拟黄瓜夏季蒸腾速率结果较为可靠且模型具有一定的鲁棒性。温室黄瓜夏季蒸腾速率随辐射强度 (净辐射 )和空气饱和水汽压差 (VPD)的增加而线性增大 ,但蒸腾速率日最大值出现时间较净辐射滞后而与VPD较为一致。

Greenhouse canopy transpiration not only has effects on greenhouse air temperature and humidity, but is also important for determination of the set point of fertigation. Penman Monteith equation was used to calculate the cucumber canopy transpiration in greenhouse under summer climate condition. The effects of environmental factors on canopy transpiration in greenhouse were analyzed based on the measurements of greenhouse microclimate factors and canopy transpiration. The results showed that Penman Monteith equation was reliable and robust in estimating greenhouse cucumber canopy transpiration under summer climate condition. Greenhouse cucumber canopy transpiration rate increased linearly with the increase of net radiation and water vapor pressure deficit (VPD) above the canopy. But the maximum value of the canopy transpiration rate occurred at the same time as that of VPD whereas about two hours later than that of net radiation. Based on the results, it was concluded that in addition to radiation, air humidity should also be considered when determine the set point of fertigation.