A Research On Improving Saline Soil By Intensive Leaching Method Inthe High Altitude Irrigation Area

Xisai irrigation area is a typical high altitude irrigation area,this area was suffering from serious secondary salinization these years.As the high altitude irrigation area salinization characteristics was special and it can hardly to improve,comprehensive improvement methods was taken into consideration,these methods are intensive leaching method and microbial technology,it was very important for saline soil improvement and prevention in Qaidam basin irrigation area.In this work,an indoor soil column experiment was conducted to simulate soil water and salt dynamics characteristics of heavy saline soil under improved by strong leaching method.Through this experiment,the desalination rate under the condition of water quota was probed.In addition,in view of the problem of poor soil productivity after desalination,the study of a microbial fertilizer pot experiment was carried out to test the ameliorate benefit of three kinds of microbial fertilizer on the improvement of soil productivity, and obtained the following results:(1)Soil salification features displayed seasonal freezing and thawing in the time and strong cohesion,the surface soil salinity degree was high.(2)The soil salt ions composition and the groundwater chemical ions composition were consistent.The formation of salt soil was affected by groundwater,the type of saline soil was sulfate and chloridate.(3)According to the comparison of three kinds of soil moisture characteristic curve,cultivated soil moisture content was minimum,waste-grassland was maximum,but water binding capacity of cultivated soil was best.(4)Intensive leaching method could effectively remove most of the salt ions,it showed very good leaching effect,especially for chloridion ion and sodium ion.The soluble ability of chloridion ion was the biggest,it reached 90.34%,sodium ion soluble ration was 90.34%.When the cumulative infiltration volume reached 650 mm, salt content in each soil layer were reduced to 2‰.The surface soil layer showed the highest soil desalinization ratios which was 82.5%.(5)Bacterial manure could improve soil fertility of saline soil after intensive leaching,and improve crop production.The ETS and MATRIX bacterial manure were better than Egypt bacterial manure.Wheat total number of spikes in ETS treatment increased 61.84%,spike grain number increased 15.27%;wheat total number of spikes in MATRIX treatment increased 94.34%,spike grain number increased 41.3%.