不同土壤水分条件下核桃的生理生态特性研究

采用完全随机设计试验方法对不同土壤水分条件下核桃生理生态特性进行研究.结果表明，土壤贮水量、耗水量、水分盈亏值均与灌水量成正比.轻剪、中剪和重剪可分别提高土壤贮水量0.2％、0.5％和0.9％，耗水量-0.5％、-2.0％和-2.5％以及水分盈亏值的1.5、1.9和2.1倍.灌水、覆草、覆膜、修剪处理下的土壤贮水量分别提高了4.4％、1.2％、1.6％和0.5％.灌水(225 kg，4月1日)、中剪、覆草、覆膜处理对增大小叶夹角、提高叶水势效果明显，重剪处理使叶绿素含量增加幅度最大（0.27 mg·dm^-2）.小叶夹角与叶水势呈正相关关系.以小叶夹角作为评估核桃树体水分状况及其立地土壤水分含量状况指标，具有可靠、直观、及时和简单等特点，并具有较高的应用价值.

Physioecological characteristics of walnut under different soil water conditions

The study with completely randomized design on Loess Plateau showed that soil water storage, water consumption, and water profit and loss had a positive correlation with the amount of irrigation. Managed with light, moderate and excessive pruning, soil water storage was increased by 0.2%, 0.5% and 0.9%, soil water consumption was reduced by 0.5%, 2.0% and 2.5%, while soil water profit and loss was increased by 150%, 190% and 210%, respectively. Under treatments with irrigation, covering with grass, mulching with plastic film, and pruning, soil water storage was increased by 4.4%, 1.2%, 1.6% and 0.5%, respectively. Irrigation, moderate pruning, covering with grass, and mulching with plastic film could increase leaf water potential and the angle between little leaf and stem, and excessive pruning could increase the chlorophyll content at most extent (0.27 mg x dm(-2)). The angle between little leaf and stem had a positive correlation with leaf water potential, which could be a reliable, direct and punctual index in evaluating the water condition of walnut and soil, and applied extensively in practice.