Salinization And Alkalinization Characteristics Of Derelict Land At Bian Wan Farm,Jiu Quan

Soil resources were non-renewable resources.With the growth of population and the acceleration of urbanization and industrialization,the shortage of land resources had become the biggest problem faced by the modern agriculture.So new agricultural land needed to be enlarged to meet the balance.It was an important way of realizing the above target to finish the soil reclamation.Study on salinization characteristics of derelict land was the important premise and fundament of reclamation,which not only helped people to recognize the causes and features of the saline soil,but also guided the improvement of the saline soil,preventing soil from the secondary salinization.There were no basic conditions for farming on BianWan farm in JiuQuan city because of the fragile ecological environment and severe soil salinization for decades.In this paper,the field investigation and indoor measurement was used for the study on the characteristics of the saline soil of BianWan farm in JiuQuan to provide the scientific basis for the soil reclamation.The conclusions as follows:?1?There was mainly sandy soil in the research area,with the large porosity.The salt content decreased and the surface assembly phenomenon of the salt became obvious as the depth of soil increased,The content of organic matter in the research area was greater than 5%,which indicated the soil had the organic matter condition of soil reclamation.?2?According to the provisional regulations of the ecological functional zone,the soil of the western regions could not be used to grow crops as it is the saline soil,whose salt content was greater 2.0%.The surface soil 0-20cm of the research sample 1-3 point was saline soil,and the surface soil 0-10cm of the research sample 4 was the saline soil,and the soil of the control alfalfa was not saline soil.So crops could not be grown on over all the research samples.Each pH was greater than 8,a typical alkaline soil.?3?Analysis on ion source of soil showed that the cations of the sample soil were from different sources,Ca²⁺mainly came from chloride salt,Mg²⁺mainly came from chloride salt and sulfate,Na⁺and K⁺mainly came from chloride salt,sulfate and bicarbonate.?4?The surface soil 0-20cm of the sample 1-2 was sulfate chloride saline soil,The surface soil 0-30cm of the sample 3-4 was sulfate chloride saline soil.The soil 20-30cm of the sample 2 was chloride sulfate saline soil;The soil 20-100cm of the sample 1 was sulfite saline soil,The soil 30-100cm of the sample 2-4 was sulfite saline soil.The surface soil 0-30cm of the control group was sulfate saline soil.The salt type of upper soil on the farm was always Ca²⁺+Mg^2+SO₄^2-+Cl^-?area A?,salt type of middle and lower soil on the farm was always between Ca²⁺+Mg^2+SO₄^2-+Cl^-?area A?and Ca²⁺+Mg^2+HCO₃^-+CO₃^2-?area B?.Research on the soil salinization characteristics of BianWan farm in Jiu Quan city helped peole to understand the salinization status of the derelict land,chosen plants and crops for saline soil amelioration.However,limited by the sampling conditions and time,limit samples could not completely represent all the farm.Therefore,it was necessary to expand the range and quantity to provide a more solid reference for the soil reclamation of the saline soil in the derelict land of JiuQuan city.