Effect Of Water Stress And Nitrogen Application On Soybean Growth And Physiological Characteristics

With four drought-resistance variety, the passage studied soybean morphological and physiological biochemical characteristics under normal irrigation and water stress. It was aim to analyze soybean growth and physiological characteristics and support theory for soybean production. The results were following.Under the condition of water stress, soybean vegetative growth reduced and strong drought-resistance soybean needed less nitrogen than weak drought-resistance soybean when it reached the best situation. Leaf relative water content, content of chlorophyll and nitrate reduction activity reduced, while leaf praline content, super-oxide dismutase, malondialdehy content and relative conductivity increased. The optimal nitrogen application and stages of different physiological and biochemical characteristics were different. Leaf photosynthetic rate and transpiration rate changed as single peak curve with the increase of nitrogen application, while leaf stomatal conductance and intercellular CO2 conceraion changed as"V"curve. Plant root fresh weight, root volume, root activity, root surface area and root active surface area were changed as single peak curve with the increase of nitrogen application. Plants per mu was stable, while pods per plant, seeds per pod, weight of 100 seeds and yield reduced. The effect of water stress on strong drought-resistance soybean was lower than weak drought-resistance soybean. In certain nitrogen application range, soybean vegetative and reproductive growth increased, or it would impeded soybean growth.