土壤水分对核桃幼树蒸腾特性的影响

The Impact of Different Soil Water Content on Juglans regia Trees' Transpiration

采用人工控制土壤水分的方法，在核桃幼树生长季对其蒸腾速率、叶温、室温、相对湿度、光合有效辐射、气孔导度进行了测定。结果表明：不同土壤水分条件下，核桃幼树蒸腾速率日变化差异显著，当土壤含水量在8％以下时，蒸腾速率的日变化不明显，土壤含水量为8％～11％时可维持其各项生理功能；通过对日蒸散量的研究，认为在该区11％的土壤含水量即可满足幼树的生长，下限值为8％。通过回归分析得出当土壤水分充足时，蒸腾速率与环境因子相关性高，反之则低。

Under the condition of controlled soil water content,transpiration rate ,leaf temperature ,room temperature, relativity humility, photo synthetically active radiation, stoma conductance of young walnut tree were determined. The results showed that different soil water contents affected obviously the daily change of the transpiration rate. The soil water content is below 8 % ,the daily change of the transpiration rate is not obvious;However,the soil water content between 11%-8 % can maintain trees＇ physiological function. Through the research of daily evapo-transpiration,we believe that when the soil water content is 11 % ,the walnut tree can grow well,the lower limit value is 8 %. The regression analysis showed that when the soil water content is sufficient to grow walnut, there is a higher correlation between transpiration rate and environmental factors,on the contrary,a lower correlation between them.