灌水量和滴灌系统运行方式对番茄根系分布的影响

Effects of Drip Irrigation and Fertigation Strategies on Root Distribution of Tomato

通过日光温室内的田间试验,探讨了膜下滴灌灌水施肥过程中不同灌水量和运行方式对番茄根系生长发育的影响。结果表明,先施氮处理（S1）的整根根长大于先灌水处理（S2）,而根表面积、根平均直径、根体积和根干质量都小于先灌水处理,且S1运行方式导致根长增加主要是由于增加了直径小于1mm根系的长度,S2运行方式导致根表面积和根体积增加主要体现在直径大于1mm的根系上;番茄约95%以上根系主要集中在0~20cm土层,且随着土层深度的增加,根系密度呈指数变化下降。S2运行方式优于S1运行方式,灌水过高或过低都不利于根系的生长发育;先灌水后施肥时,总灌水量为1 600m3/km2是最佳的水氮管理模式。

Field experiments were conducted in a greenhouse to explore the effects on the growth and development of tomato roots under different irrigation amounts and fertigation strategies in the process of drip irrigation under plastic film.The results showed that the whole root length for the strategy of applying nutrient at the beginning（S1）was greater than that for the strategy of applying water at the beginning（S2）,but the surface area,average diameter,volume and dry weight of root were less than those for the strategy of applying water at the beginning.S1 operation mode resulted in the increase of root length,which was mainly due to the increase of root diameter less than 1mm,while S2 operation mode led to the increase of root surface area and root volume,which was mainly reflected in the root diameter greater than 1mm;95%of total root length was concentrated in the 0~20cm soil layer and the root length density decreased exponentially with the soil layer increasing.S2 operation mode was better than S1 operation mode,both too high and too low irrigation mount were not conducive to the growth of root system;The total irrigation amount of 1 600m3/km2 was the best optimal pattern with fertilization after irrigation.