摘要
采用电子称重蒸散计逐日测定临泽北部绿洲玉米生育期的蒸发蒸腾量,结果表明:玉米的越发蒸腾量在充分供水条件下为813.6mm(日均5.18mm),在少量供水条件下为580.9mm(日均3.70mm),蒸散系数分别为260和273。地面蒸发量与作物蒸腾量比值约1:4。田间小气候对作物蒸发蒸腾的影响是综合性的,其中太阳辐射是影响作物蒸发蒸腾的主导因子。气孔扩散阻力与蒸腾速率呈负相关关系。作物蒸腾加速时叶水势下降,反之则水势升高。初步结论认为,气孔扩散阻力和叶水势可作为土壤-植物-大气系统水循环的重要参数。
Evapotranspiration (ET) of maize plant during the developmental stages was measured with electronic weighing lysimeters. The results show that the crop ET varied with watering conditions and reached its maximum in the blooming-grouting period. The ratio ground evaporation to maize transpiration is 1:4. Influence of field micro-climate to crop ET is comprehensive, and solar radiation plays a leading role. Stomatal diffusion resistance is negative correlated with the rate of crop ET . Leaf water potential decreases along with the acceleration of crop ET. Our preliminary conclusion is that stomatal diffusion resistance and leaf water potential would be the two important parameters of soil-plant-atmospheric water circulation.
关键词
玉米
蒸发
水势
蒸腾
Evapotranspiration
Weighing lysimeter
Water potential
Stomatal resistance
