修剪对黄土丘陵区枣树蒸腾的调控作用

Effect of Trim on Jujube Transpiration in Loess Hilly Region

对枣树树体进行梯度修剪,采用热扩散探针(TDP)液流监测系统和中子水分仪对枣树的蒸腾和土壤水分进行同步动态监测,通过2年连续监测发现:修剪对枣树不同时间尺度上的蒸腾均有显著影响。修剪可以显著降低枣树开花坐果期和果实膨大期的树体蒸腾,降低对土壤水分的消耗。与对照处理相比,轻度、中度和重度修剪的枣树全生育期蒸腾总量分别下降31.7%、52.0%和68.6%。通过线性和非线性的分析方法,分析了蒸腾和树体规格指标之间的关系,构建了自然降水量和修剪目标产量的数学模型。提出适宜的陕北枣林可持续经营的目标产量为1.2×104kg/hm2,适宜的节水型修剪调控树体指标为冠幅体积和新稍长度。

In order to alleviate the soil drying of the jujube forest in semiarid loess area,we took the gradient control on jujube tree specifications by pruning,using the TDP tree rod liquid flow monitoring system to monitor the jujube tree transpiration and CNC100 neutron moisture meter to monitor soil moisture. It was found that the pruning on jujube had a significant influence on the transpiration and water consumption at different time scales through the research for two consecutive years. Pruning can significantly reduce the tree transpiration in flowering period of fruit and fruit enlargement period of jujube,and reduce the consumption of soil moisture. Compared with the control treatments,the tree transpiration with mild,moderate and severe pruning of the whole growth period decreased by 31. 7%,52. 0% and 68. 6%,respectively. The relationship between tree transpiration and specifications were analyzed by linear and nonlinear analysis method,and then a mathematical model of natural precipitation and trim production target was built. The suitable target yield for the sustainable management of jujube forest in northern Shaanxi was 1. 2 × 104 kg / hm2,and the tree index for water-saving trim regulation was the crown and the new length. The new mode was formed that the production of jujube was determined by soil moisture and jujube specifications were determined by production.