枣树与紫花苜蓿间作模式的根系分布及土壤理化性质研究

Root distribution and soil physicochemical properties of jujube tree and alfalfa intercropping model

摘要:

【目的】 研究枣树间作紫花苜蓿的根系分布情况、枣树的侧根分布情况和土壤理化性质，为成龄果林行间间作牧草提供科学依据。【方法】 以14年枣树园为试验地，在行距为5 m×5 m的果树行间播种紫花苜蓿，培育3年后随机选取3个1 m×1 m土壤剖面测定枣树、紫花苜蓿的根系生物量，测定土壤pH值、电导率、有机质等土壤理化性质。【结果】 枣树根系垂直深度达到140 cm，侧根生物量在土壤中的垂直分布主要集中在40~80 cm土层。紫花苜蓿在不同土层的根系分布情况呈倒金字塔型，根系深度达到160 cm，根系生物量主要分布在0~40 cm。与枣树清耕地相比，枣树间作紫花苜蓿模式可降低0~40 cm土层的pH值，可降低0~60 cm土层的电导率，可有效增加0~40 cm土层的有机质含量。 【结论】 枣树间作紫花苜蓿的栽培模式，可以改善枣树果园的土壤理化性质，促进土壤有机质的积累， 有利于促进枣树和紫花苜蓿的生长发育。

Abstract:

【Objective】 To study the root distribution，lateral root distribution，and soil physicochemical proper ties of alfalfa under intercropping of jujube trees，providing a scientific basis for forage cultivation in mature fruit or chards.【Method】 A 14-year-old jujube orchard was used as the experimental site. Alfalfa was sown between rows of fruit trees with a spacing of 5 m×5 m. After 3 years of cultivation，three 1 m × 1 m soil profile plots were ran domly selected to measure the root biomass of both jujube trees and alfalfa，as well as soil pH value，soil conductivity， soil organic matter，and other soil physicochemical properties.【Result】 The jujube tree's root system extended verti cally to a depth of 140 cm，with lateral root biomass in the soil mainly concentrated at 40~80 cm. Alfalfa roots in dif ferent soil layers exhibited an inverted pyramid distribution shape，reaching a root depth of 160 cm， with most of the root biomass located in the 0~40 cm layer. Compared with the monocropping of jujube trees，intercropping alfalfa with jujube trees slightly reduced the soil pH value in the 0~40 cm soil layer，significantly decreased soil conductivity in the 0~60 cm soil layer，and effectively increased soil organic matter content in the 0~40 cm soil layer. 【Conclusion】 Intercropping jujube trees with alfalfa is a feasible cultivation strategy. Although there may be local competition between the two root systems，this approach can improve the soil physicochemical conditions of jujube or chards and facilitate the growth and development of both jujube trees and alfalfa.