The Research On Quality Evolution Of The Artificial Oasis Soil On The Eastern Edge Of Ulan Buh Desert

This article analyzed the physical-chemical nature of the artificial oasis soil on the eastern edge of Wulanbuhe desert in Multi-level and multi objectives, through the field investigation and the indoor tests, with the application of space and time correlation method, to explore the soil quality evolution situation during the artificial oasis advancement (1980-2008).The analysis resulted as follows:(1) The coarse sand content of soil (0-10cm) dropped from 19.7% in 2008 to 3.8% in 1980; The silt total content increased from 11.3% to 40.7%, the clay content increased from 0.2% to 3.0%, the soil powder sticking percentage dropped 83.7%, the average dropping percentage is 6.7% every year, the powder sticking percentage fitted curve equation is y=1.31375x2-20.558x+97.423, R2=0.9574, it assumes the significance relations. Other sand grains, the silt, the clay content of each layer changes similarly.(2)The organic matter of soil surface layer (0-30cm) compares with the comparison increased by 4.95g/kg, the average increscent is 0.18g/kg every year, the yearly increasing rate is 13.4%; The entire nitrogen quantity of soil surface layer compared with the comparison grows 0.52g/kg, the entire phosphorus increscent is 0.088 g/kg, the entire potassium increscent is 0.951 g/kg; The fast-acting nitrogen of soil surface layer increscent is 25.90 mg/kg, the fast-acting phosphorus increscent is 1.824 mg/kg, the fast-acting potassium increscent is 139.4 mg/kg, other changing of each layer is similarly.(3)The entire salt quantity range fall of the soil surface layer is 0.655%, the pH value of the 0-10cm surface layer drops from 8.5 in 1980 to 8.1 in 2008, the changing tendency of the entire salty quantity and the pH value is dropping overall.(4) soil Ca2+ content increased by 0.749mmol/kg, Mg2+ content increased by 0.169mmol/kg, the Na++ K+ content dropped by 9.52mmol?kg, SO42- increased by 0.091mmol?kg, Cl- reduced by 1.727mmol?kg, the HCO3- content in the soil assumed the obvious dropping tendency, it might be explained that the advancement of HCO3- has transformed into CO32- in the oasis, and has formed precipitation with two price calcium magnesium heteropolar ,then fix in the soil layer.(5)Na+?Ca2+ value reduced by 86%, the soil biogeochemistry circulation transformed from the sodium circulation into the calcium circulation, and the soil salinity is neutral salt (Na2SO4 and NaCl ) primarily.(6) The Sa value of soil increased by 1.41 from farm One to Four, the soil quality of One surpasses Four, during the time advancement, the Sa value reduced by 19%, and the increasing of Sa value reflects that the soil is in the growth evolution.(7) The H/F value from farm one to four has increased by54.5%,it showsthat the soil quality in farm one is higher than it in four.The HuFu comparison had reduced from 1.44in 2008,it dropped by37.5%.The dropping of the H/F value indicates that the soil is in progress.(8) Using the principal components analytic method to do the synthetic evaluation of the physical-chemical nature of soil in the artificial oasis process, the result shows that: The synthetic evaluation value of soil quality has obvious increasing tendency, namely the artificial oasis process may improve the quality of wilderness soil.