Drip Irrigation Depth Alters Root Morphology and Architecture and Cold Resistance of Alfalfa

Combined stress from water and temperature is considered an effective approach for improving the cold resistance of alfalfa (Medicago sativa L.). However, relationships among irrigation depth, root morphology architecture, remain unclear. In this study, we investigated effects drip at soil surface (Deep-0), 20 cm depth (Deep-20), 40 (Deep-40) on architecture alfalfa. The Deep-0 treatment had highest aboveground biomass belowground biomass, system in Deep-40 tended to a ‘herringbone’ branching type, which increases cost uptake. After acclimation 3 days, was strongest, associated with higher soluble sugar content fewer reactive oxygen species roots. enhanced severity drought crown increased risk exposure low-temperature stress. results showed that promoted growth development by regulating absorption efficiency, thereby enhancing ability withstand