供水条件对温室番茄根系分布及产量影响

通过田间试验，分析了不同生育期供水条件对番茄灌水量、光合作用、根系分布、产量和水分利用效率的影响。结果表明：番茄开花坐果期控制灌水下限为60%f_C(田间持水量)，结果盛期控制灌水下限为75%f_C，控制灌水上限为90%f_C，番茄产量最高，达到91.7 t/hm²，水分利用效率达到27.51 kg/m³，整根的根长、根表面积、根体积、根干重都明显增加。叶片净光和速率在75%f_C条件下最高，有利于光合产物的形成。随土层深度的增加，根长密度呈指数下降。不同土壤水分条件对番茄根系生长影响主要体现在直径小于1 mm的根系上，而且直径小于1 mm的根长和产量之间存在很好的相关关系。

Impacts of different water supply on tomato root distribution and yield in greenhouse

The impacts of different water supply conditions in different growth stages on tomato irrigation amount, net photosynthrtical rates, root distribution, yield and water use efficiency were analyzed through field experiment. Results show that the yield can attain 91.7 t/hm² and the water use efficiency reaches 27.51 kg/m³ when the lower limit are 60% and 75% of the field capacity at the flowering and fruit bearing stage, fruit stage, respectively. The total root length, surface area, volume, net weight and root length density significantly increases under this lower limit treatment. The highest net photosynthrtical rates occurrs under 75%fc. The density of root length declines exponentially with the increase of the soil layer depth. Different water conditions influence the growth of tomato root obviously. A good correlation between tomato yield and the ratio of the root length with diameter of less than l mm is better.