渭北旱塬小麦根系的再生能力及其意义

在降水少、水土流失严重的渭北旱塬所进行的试验表明：经历冬、春于旱危害的小麦，分布在耕层以内的密集的根都枯黄萎缩，根表皮细胞全部破皱剥落，完全丧失了吸收功能，只有输导组织仍然健全。

Ability and Significance of Wheat Root Regeneration in Weibei Rainfed Tabl e1 and

Under very dry condition, the winter wheat roots in cultivated soil layer withered in spring, the epidermis, except the vascular tissue, damaged. This showed that the roots lost their absorbing ability.The roots in deep soil layer have the absorbing ability because the deep soil layer is damper, but the water and nutrient that absorbed by the roots in deep soil layer can not meet the need of wheat growth and development.for the roots and nutrient in deep soil layer are less than those in cultivated soil layer.So, the yield was very low.After the rainfall in the turn of green stage and jointing stage, the damaged roots can not recover, but winter wheat has the ability of producing new secondary roots to recover its absorbing ability.In this stage, the root system had strong compensation absorbing ability.Thus, it is an effective measure to raise the effects of water and fertilizer on dryland winter wheat through applying nitrogen fertilizer in spring ram.