Study On The Repair Function For Soil By The Halophytes Rhizosphere Under Salt Alkali Stress

In our country, the saline-alkali soil is distributed widely and has a large area, adding to the secondary salinization caused by improper cultivation, the salinization of soil becomes more serious. It has already affected the development of agriculture and stockbreeding. Improving saline alkaline soil by using the Bio-repairing technology is feasible way. But the reasearch about the repair function for saline-alkali soil by the halophytes rhizosphere is still in the investigating stage. In the paper, choosing the Binhai saline-alkali soil in Dagang of Tianjin as the research object, through the research about the change of soil character after planting halophyte, ensure the repair function for saline alkaline land by the halophytes rhizosphere under salt alkali stress, and offer the theory evidence for halophyte exploiture and the improving of saline alkaline soil by using the Bio-repairing technology.1. The effect of the halophytes rhizosphere on nutrition composition of saline alkaline soil The experiment mensurated many characters, including the content of organic, nitrogen,quick-acting nitrogen, phosphorus, quick-acting phosphorus and potassium, quick-acting potassium. The results indicated that, the organic content in the halophytes rhizosphere has an obvious increased, raised 74% in the Tamarix chinensis rhizosphere. The content of nitrogen, quick-acting nitrogen, phosphorus, quick-acting phosphorus and potassium, quick-acting potassium in halophytes rhizosphere has an obvious decrease, because the halophytes growth need them, and absorb them by the root. But the content increase after halophytes growthed in a degrees.2. The effect of the halophytes rhizosphere on physical and chemical characters of saline alkaline soilThe experiment mensurated the water content, pH and salinity content. The results indicated that, the water content in halophytes rhizosphere has an obvious increase. The mostincrease is 6.6%. The pH and salinity content in halophytes rhizosphere reduced in various degrees. The physical and chemical characters of saline alkaline soil have obvious improvement.3. The effect of the halophytes rhizosphere the amount of microorganism in saline alkaline soilThe amounts of microorganism have mensurated through the experiment. The microorganism includes bacillus, epiphyte and actinomycetes. The results indicated that, the amount of microorganism in the halophytes rhizosphere has an obvious increase than the non-rhizosphere soil. The amount of epiphyte rose two times in the Tamarix chinensis rhizosphere. And with the development of the the plant root system, the amount of the microorganism is trend to rise.4. The effect of the halophytes rhizosphere on activity of soil enzyme in saline alkaline soil The experiment mensurate the activity of soil enzyme, include urease, lipase, sucrose enzyme and amylase. The results indicated that, the activity of soil enzyme in the halophytes rhizosphere has an increase in various degrees than the non-rhizosphere soil. The activity of urease rose 50.7% in the Tamarix chinensis rhizosphere. And with the time increasing, the activity of soil enzyme is trend to rise.5. According the results on the characters of different halophytes rhizosphere, we consider Tamarix chinensis is good at improving the saline alkaline soil. It can grow easily, so it has good foreground of the planting and the development.