膜下滴灌条件下不同灌溉量对番茄根系分布和产量的影响

采用分层挖掘法，对膜下滴灌5 426 m³·hm^-2（W1)、4 419 m³·hm^-2（W2）、3 700 m3·hm^-2（W3）3个灌溉量下番茄根系分布特征和产量进行了研究。结果表明：随灌水量的减少，番茄根系表现出向深层发展的趋势，符合“水大根小”的特征，根长、根表面积、根长密度随着土壤深度的增加均呈“单峰型”曲线：即灌水量愈少，根长、根表面积、根长密度的峰值愈位于土壤的深层；番茄根冠比也随着灌水量的减少而呈增大的趋势，W2处理、W3处理分别比W1处理提高了26.53%和70.71%；适度的控制灌溉水量可以促进根系的生长发育,扩大水分吸收空间,有利于番茄增产，4 419 m³·hm^-2灌溉量是膜下滴灌最适宜灌溉水量。

Effect of Drip Irrigation Quota on Root Distribution and Yield of Tomato under Film Mulch

An experiment of effect of different drip irrigation quotas (W1: 5 426 m3·hm-2; W2: 4 419 m3·hm-2; and W3: 3 700 m3·hm-2) on roots distribution and yield of tomato under film mulch was conducted with delamination excavation method at the Experimental Station of Agro-Ecology Engineering Institue of Gansu Agricultural University. The results showed that, with the decrease of irrigation quota, the tomato roots tend to distribute in deeper soil layers, which accords with the characteristics of "shallow roots when more irrigation". Also with the decrease of irrigation quota, the maximum values of root length, root surface area, and root length density all move deeper, and the root/shoot ratio increases. Comparatively, the root/shoot ratio in treatments WC2 and WC3 is 26.53% and 70.71% higher than in WC1, respectively. Therefore, proper irrigation quota is beneficial to root growth and expansion of water absorption space, which could results in the increase of tomato yield. The experiment demonstrated that the irrigation quota of 4 419 m3·hm-2 of irrigation is the optimal in drip irrigation under film mulch.