Analysis And Study On Water And Fertilizer Coupling Mechanism Of Alfalfa In MaoWuSu Sandy Land

Maowusu sandy land located the wushenqi of Erdos City In Inner Mongolia from China, because of local of bad weather conditions and excessive overload grazing, local ecological system was subjecting of serious damage-pasture degeneration, land desertification, hay growth serious cound not meet the local development of animal husbandry. However,alfalfa as a perennial herbaceous plants of legume was widely distributed in arid and semiarid region in our country, because of its high yield, high quality and high protein alfalfa was reputed to the king of grass and the green gold.This paper considers the actual conditions of soil fertility barren in maowusu sandy land, analysis of alfalfa, reduce the coupling effect physiological indexes, hay nutrients and soil nutrient influence. Get the following conclusion:1. In the whole growth period, the plant height of alfalfa is in a "slow-fast-slow growth" S type dynamic growth curve. Variance analysis of the plant height shows:in the green returned stage, the significant differences is small between every treatment; from the beginning of each branch, the significant differences(P<0.05) is bigger and the significant difference (P<0.01) is smaller than every treatment in the green returned stage;To the flowering period,the significant difference (P<0.01) of every treatment is the most biggest.2. The relationship between the yield of alfalfa and the constitute of the yield elements is:the plant height,the stem diameter and the leaf area is increasing with irrigation water and fertilizer quantities increased, the rates of stalk and foliage is reducing with the irrigation water and fertilizer quantities increased. Fertilizer effect order fiom high to low: potassium compound fertilizer effection>1/2compound fertilizer+l/2ureophil fertilizer effection> potassium ureophil fertilizer effection3. The relationship between the quality of alfalfa and the constitute of the quality elements is:the crude protein and the crude fat content of alfalfa is rising with the increasing of the fertilizer quantities, the crude protein and the crude fat content of alfalfa is reducing with the increasing of the irrigation water quantities; Crude fibre content of alfalfa is reducing with the increasing of the fertilizer quantities,the crude fibre content of alfalfa is rising with the increasing of the irrigation water.Potassium compound fertilizer to improve the quality of alfalfa, the effection is good.4. In the three kinds of appling fertilizer mode, the total N content of the soil is rising with the increasing of the fertilizer quantities, the rapidly-available P and the rapidly-available K content of the soil are rising with the increasing of compound fertilizer quantity and1/2compound fertilizer+l/2ureophil fertilizer quantity, the effection is less for the rapidly-available P and the rapidly-available K content when only spread manure of ureophil fertilizer on the soil.Three kinds of application mode have affected on improving organic matter content of the soil, but their diversities are small each other.5. According to above analysision, know that the plant is high, the yield is high, the hay palatability and quality is good, the soil’s improvement effection is remarkable.this treatment is:in potassiuming compound fertilizer mode, irrigation water quantities is3600m3/hm2, fertilizer quantities is120kg/hm2, this treatment is the best.