Abstract:

The problems of soil salinization have been getting serious gradually and the area of the abandoned salinized fields were constantly expanding which were influenced by the climate factors and the human activities in arid irrigated areas, China. The studies on variance rule of soil salt and soil nutrients were carried out on the different abandoned fields in order to provide theoretical basis for the soil restoration and reasonable use of the abandoned salinized fields. Minqin oasis which is located in Lower Reaches of Shiyang River is classified serious area of soil salinization. The variation characteristics of soil nutrients (soil organic matter, total N, rapidly available P and K) and salinity (Ca2+, Mg2+, K+, Na+, CO32-, HCO3-, Cl-, SO42-) of different rear abandoned fields that was abandoned in different years were researched by the method of space series replacing time series. The results showed that length of abandoned time had different degree of influences on soil nutrients and salinity. The content of soil organic matter was higher with 5 years. The content of soil organic matter was minimum with 5-10 years, and the content of soil organic matter was tending towards stability after 10 years. The content of total salinity ascended higher and higher with the increasing of the abandoned time. The main cation were Cl-, SO42- among 8 ions, but main anion were K+, Na+, respectively accounting for 66.2% and 19.2% of total salinity. The degree of salinity became more serious as time prolonging.