Abstract: Studies with the seedlings of two poplar clones (NL-80105, NL-80351) and willow show that under soil waterlogging, the root number was decreased, root length was shortened, root activity was declined, height growth became slow, and correspondingly, the biomass was decreased.Leaf stomas had a strong response to waterlogging stress, which affected the activity of nitrate reductase in leaves.Willow had a stronger waterlogging resistance than poplar, no matter on growth or on physiological properties.

Key words: Poplar, Willow, Waterlogging stress, Growth, Physiological properties, AquaCrop model, canopy cover degrees, nitrogen application rate, whole plastic-film mulching on double ridges, grain yield