Physiological And Growth Characteristics And Nutrition Features Of Amorpha Fruticosa Under Salt Stress

Today, soil salinization is one of the serious problems which the world is facing and also the the most difficult problems to be solved in degradation. The improvement of saline soil is an urgent problem to be solved.Amorpha fruticosa is a shrub with greater resistance to stress, it grows normally in the soil which is very high salt conten. It has strong resistance to salt, and could also reduce the extent of soil salinization significantly, In this research, physiological characteristics of A. fruticosa leaves under different salt contents, such as photosynthetic rate, enzyme activity, organic osmolytes and so on were studied under artificial controling soil salinity gradient. The mechanism of salt tolerance about A. fruticosa was also discussed, In order to find the theoretical way of saline soil improvement, the sample spots were chosen from Linze experimental station of Lanzhou University which locates in Linze country in Gansu province in China. We planted A. fruticosa there and studied the effect of A. fruticosa on the improvement of soil salinization.The main conclusions are as follows:1.In A. fruticosa leaves, with salt concentration increasing, SOD activity, contents of free praline and MDA, and photosynthetic pigment content all increased, and the maximum value all appeared when the salt concentration is 0.5%-0.6%. In particular, free praline content at 0.5% salt concentration is 7.8 times than that of the control. These results indicated A. fruticosa has some adaptability in saline environment.2. As the increase of salt concentration, Na+ content of A. fruticosa leaf increased while K+content decreased, however, the content of K+obviously higher than Na+. this result also indicated that A. fruticosa has some adaptability in saline environment.3. Planting result in saline soil of Hexi shows that A. fruticosa growing well, and its nutrients are high, especially nitrogen, phosphorus and potassium are higher than the average plant. Planting A. fruticosa plays the role of covering surface, reduceing water evaporation, relieving accumulation salt transferring through dry climate, also inhibits the aggregation of soil deep salt to the surface, all these reducd the accumulation of salt in soil. For 1-year-planting field, soil layer desalination rate of 0-10cm and 10-20cm were 20.75%and 20.61%respectively. For 2-year-planting field, soil layer desalination rate of 0-10cm and 10-20cm were 28.37% and 29.45% respectively. Summary, planting A. fruticosa in saline soil is an effective biological measures for improving saline soils.