枣棉间作系统枣树根系空间分布特征研究

目的]对环塔里木盆地中心地带——阿克苏市的枣-棉花间作系统枣树吸收根根系空间分布特征进行研究,以期为枣-棉花间作系统枣树根系吸水运移模型的建立、枣树保护带宽度的确定及田间灌水、施肥技术的改进提供基础资料.方法]采用根系分层挖掘法,挑拣每一个土层样方内的活根,清洁、阴干、分类、扫描,并用专业软件对根系长度等指标进行测定分析.结果](1)垂直方向上,枣树吸收根根量主要集中在0～ 120 cm土层内,约占总量87.09;；(2)水平方向上,主要分布在距枣树树干0～150 cm范围内,占总量的83.67;；(3)根据棉花根系的分布,得到枣树与棉花根系分布密集区在距枣树100～150 cm、土层深度0～80cm的范围内.结论]保护带的设置对于枣树根系的生长、缓解枣树与棉花间水分、养分的竞争有极其重要的作用,而保护带宽度的设定值得探讨,需要根据枣树的年龄、冠幅等进行综合判断.就此试验地的情况来看,在不改变该试验地枣树保护带宽度的条件下,枣树的施肥区域应在距枣树树干100～ 150 cm.

Spatial Distribution Characteristics of Jujube Tree Roots in the Jujube-cotton Intercrooping System

【Objective】The spatial distribution characteristics of jujube tree fine roots in the jujube-cotton intercorpping were analyzed in order to provide the basic documents for constructing the model of water uptake by roots,and for determining the width of jujube protection and improving irrigation and fertilization technology.【Method】Root excavation was used and a soil sample for each side of the live root was picked,cleaned,dried,sorted,scanned.Specialized software was used to measure and analyze the root length and other indicators.【Result】(1) In the vertical direction,jujube trees fine roots are mainly distributed in the soil layer of 0~120cm,accounting for 87.09% of the total;(2) in the horizontal direction,they are mainly distributed in the range of 0~150cm between the jujube trees,accounting for 83.67% of the total amount;(3) according to the distribution of cotton roots,jujube and cotton roots are mainly distributed in the range of 0~150cm between the jujube trees at the depth of 0~80cm of the soil layer.【Conclusion】Establishment of protection for root growth of the jujube trees played an extremely important role in the relief of the water and nutrient competition between cotton and jujube trees,but the width of protection setting is still worthy of further consideration,which would be involved in the comprehensive judgments of jujube tree age,crown,etc..In view of the present test situation,the zone of fertilization to jujube trees should be within the range of 100~150cm without changing the test protection.