Study On The Integrated Modeles Of Different Technologies For The Improvement Of Saline Alkali Land

With a view to proven up the single Saline-alkali soil improvement measurement contribution among the integrated methods, The studies were carried in field and pot experiment condition and crop growing under paddy field and dry field condition in North of Yingchuan, a typical Saline-alkali soil named takyr solonetzs, and the integrated methods combined the individual measurement from water conservancy engineering, chemistry, agronomy and biological improvement technology according paddy and dry field characteristic. The results were analyzed on different integred modeles on soil physical and chemical properties and plant growth impact on physiological and biochemical to clear the effect of desulfurized gypsum, modifier, organic, fertilizer, irrigation, sand and crops （rice and alfalfa） on saline-alkli soil improvement, and to set up a suitable integrated model for paddy field and dry field soil improvement. The main conclusions are summarized as follows:1. Studies on the integrated model on paddy field saline-alkali soil improvement（1） Application of FGD gypsum and modified agent could decrease soil pH value, alkalinity, a slight increase of the salt content, which could increased Ca²⁺, Mg²⁺, SO₄^2- and decreased the content of K⁺, Na⁺, Cl^-, CO₃^2- and HCO₃^-. Application of organic could improve the available of soil potassium, phosphorus, nitrogen and organic matter content. Irrigation could decreased the soil alkalinity 51.16% by shower, and reduced the salt content 4.74 g/kg, the soil available potassium decreased more significantly if cormpared with rice planting on the effect of soil salt and soil nutrient content.（2） Rice planting treatments also showed that application of FGD gypsum+ modifier, organic fertilizer could promote rice growth. T9 as integrated model had highest yield of 9307.1 kg/hm², which was 160.6 kg/hm² higher than T7 （Application of FGD gypsum and modified agent）;and 2471.3 kg/hm² higher than T4 （organic fertilizer）.（3） The rice yields of different integrated models were increased as E>D>OB>A, and A was the control treatment had the lowest yield of 526.9 kg/hm², The treatment of E （the application of FGD gypsum+conditioner+organic fertilizer+sand） had the highest yield of 3131.9 kg/hm². So the treatment E (2.25 desulfurization gypsum x 104 kg/hm²⁺modified agent 7.5 x 103 kg/hm²⁺organic fertilizer 3 x 104 kg/hm²⁺sand 3 x 104 kg/hm²) should be took as best integrated methods on Saline-alkali soil improvement under paddy field condition.2. Studies on the integrated model on dry field saline-alkali soil improvement（1）The application of desulfurization gypsum can decreased soil pH, and increased the soil total salt content; and Irrigation leaching also could decrease soil total salt content; but the application of desulfurization gypsum and irrigation leaching could accelerat the soil salt decrease.（2） The application of desulfurization gypsum could significantly effect on soil improvement, but the effect could be increased with one or two years after the application, especially on using the improved agent and organic fertilizer, which could improve the yield of alfalfa greatly.（3） The alfalfa yields of different integrated models were ranked as Tr5>Tr4>Tr3>Tr2>Trl>CK, here the alfalfa yield of Tr5 was 92.9% higher in first year after treatment,109.8% higher in second year after treatment,3and 127.1% higher in third year after treatment if compared with it’s control. So the Tr5[application of FGD gypsum 2.25 x 104 kg/hm²⁺ modifier 7.5 x 103 kg/hm²⁺ organic fertilizer 3 x 104 kg/hm² irrigation and drainage measures （leaching irrigation quota:4.05 x 103 m3/hm²; irrigation for salt leaching after 4-6 hours drained）] should be took as best integrated methods on Saline-alkali soil improvement under dry field condition.The results also showed that the soil improvement effect on rice planting was better than on alfalfa planting by compared on paddy field and dry field condition.