间作条件下杏树吸收根空间分布特征

Spatial Distribution Characteristics of Absorbing Roots of Apricot Trees in the Intercropping Systems

【目的】分析绿洲灌溉条件下杏农间作系统中杏树吸收根空间分布，以期为新疆南疆盆地杏农间作杏树水肥管理提供科学依据。【方法】采用剖面挖掘和分层取样法，利用WinRHIZO Pro2009a根系分析系统对间作条件下15a生杏树吸收根的空间分布进行了分析。【结果】在水平方向上（0～300cm），杏树株间吸收根根长密度随离树干距离的增加呈递减趋势，最大根长密度分布在距离树干0～50cm，行间则是先略有增大后减小，最大根长密度分布在距离树干50～100cm，吸收根根长总量株间仅比行间少1．11％；在垂直方向上（0～150cm），杏树株间和行间吸收根根长密度均随着土层深度的增加先增大后减小，吸收根最大根长密度株间分布在20—30cm土层，行间则分布在30～40cm土层。【结论】绿洲灌溉条件下，杏一麦间作系统杏树株间和行间吸收根空间分布存在差异，但总量相差很小。行间距离树干0～120cm的0～60cm土层是杏一麦间作系统田间水肥管理的重要区域，盛果期杏树株行间施肥位置应在树冠冠下的2／3～4／5处，行间施肥深度（30．50cm）应比株间施肥深度（20～40cm）深约10．20cm。

[Objective] The Purpose of this article is to provide scientific basis for its water and fertilizer management in South of Xinjiang under the condition of oasis irrigation, through analysis of the spatial distribution characteristics of apricot tree absorbing roots in apricot-wheat intercropping systems. [Method]With profile digging and layered sampling methods, the spatial distribution of absorbing roots of 15 - year - old apricot trees in the intercropping systems is analyzed by using WinRHIZO Pro2009a analysis system. [ Result] In horizontal directions （0 - 300 cm）, the length density of the absorbing roots in the rows is decreasing with increasing distance from the trees. The maximum root length density is in the 0 - 50 cm from the trees. The length density of the absorbing roots between the rows is slightly increasing first, and then decreasing with increasing distance from the trees. The maximum root length density is in the 50 - 100 cm from the trees. The total length of the absorbing roots in the rows is only less 1.11% than it is between the rows. In vertical directions （0- 150 cm）, the length density of the absorbing roots in the rows and between the rows is increasing first, and then decreasing with increase of soil depth. The maximum root length density in the rows is in the 20 - 30 cm soil layer, and between the rows is in the 30 - 40 cm soil layer. [ Conclusion]Under the condition of oasis irrigation, the spatial distributions of apricot tree absorbing roots are differences between intra- row and inter- row in the intercropping systems, but the differences of total length of the absorbing roots are small. The 0 - 60 cm soil layer in the 0 - 120 cm from the trees is important for water and fertilizer management in apricot - wheat intereropping systems. The position of fertilization in the rows and between the rows should be under the crown 2/3 -4/5 site at the prosperous fruit stage of apricot trees. The fertilization depth between the rows （30 - 50 cm） should be deeper about 10 - 20 cm than in the rows （20 - 40cm）.