立体种植农田不同生育期及土壤水分的根系分布特征

Root Distribution in Strip Intercropping Field under Different Growth Period and Different Soil Water

在立体种植农田中，作物根系分布是影响作物间水肥竞争及利用效率的首要因素。针对滴灌条件下番茄套种玉米立体种植农田设置高（T1）、中（T2）、低（T3）3个土壤水分处理，研究不同水分处理对立体种植农田不同位置土壤含水率、作物根系分布的影响，探讨立体种植农田根系在不同生育期生长发育特征。结果显示：立体种植农田番茄侧土壤含水率平均值显著低于玉米侧，膜内土壤含水率明显高于膜外土壤含水率，膜内不同位置土壤含水率无明显差异；随着生育期的推进作物间根系呈“不交叉一轻度交叉一完全交叉一轻度交叉”规律；随着土壤含水率的增加根系总量呈增长趋势，在0～30cm的滴灌湿润区，作物根系分布最密集，约占总根系的60％～70％，且高水分处理根量显著大于低水分处理，根长密度、根表面积密度、根体积密度以及根重密度均呈现T1〉T2〉T3的趋势，而在非滴灌主要湿润区则正好相反；累积根系分布曲线分析显示随着土壤含水率增加根系向土壤下层生长，随着生育期推进根系向作物中间发展。立体种植农田作物在不同生育期根系分布变化明显，同时土壤水分对根系分布影响较大。

It is the primary factor to influence the completion and utilization efficiency of water and fertilizer for the root distribution in strip intercropping field. The effects of 3 treatments of high, middle and low irrigation quotas on soil water of different positions and root distribution were studied, and the characteristics of root distribution in different growth period were investigated, as well as the pattern of root distribution in vertical and horizontal direction based on cumulative root distribution curves. The results show that the average soil water in tomato side is obviously higher than corn side, and the soil water under mulch is also obviously higher than that under outside mulch; however, there is no significant difference for the soil water of different positions under mulch. With crop growth, there are the pattern of ＂no cross--small cross--full cross--small cross＂ for roots of tomato and corn; 60% - 70% root concentrates in 0 ~ 30 cm soil, and the quantity of total roots and the roots in 0 - 30 cm soil are all increasing with the soil water, whatever root length density, root surface area density, root volume density and root weight density, yet there is the inverse for root distribution in 40 ~ 100 cm soil. The cumulative root distribution curves show that the root grows down with the soil water increase and the root grows to the district omong crops with crop growth except for corn in the last stage. The root distribution is large variation in different growth periods, and the soil water is also main factor to influence root distribution in strip intercropping field.