Development Law And Prevention And Control Technology Of Soil Salinization In Alar Region,Xinjiang

Soil salinization is an old problem.It can be said that since the 1950s,the process of construction and development of xinjiang production and construction corps is the process of fighting against soil salinization.In the new era,the southward development of the xinjiang production and construction corps has become a national strategy.The construction of ecological civilization and high-quality development have put forward higher requirements for the planning,development,utilization and control of land space.Based on the comprehensive geological survey project of south xinjiang region of China geological survey bureau and taking the arar area of XPBC city as the research object,this paper reveals the law of soil salinization and puts forward the new technology of soil salinization prevention and control.Major achievements include:1.Developed a soil salinization identification and rapid evaluation technology based on multi-spectral remote sensing data.From the field collection of typical samples,spectral testing and salt content testing,the establishment of soil salinization identification and severity interpretation mark,to the small-scale interpretation verification,and then to the regional promotion,the formation of relatively mature and precision to meet the requirements of technical methods.2.The distribution law of soil salinization development in the study area was identified.Soil salinization in the aral area of xinjiang are mainly distributed in the north of 8,9,10 herd and aksu river,on both sides of the tarim river alluvial plain,and the reservoir surrounding,salinization land accounted for about 62%of the total area,salinization of soil chemical types are mainly composed of saline soil and sulfurous acid sulfate saline soil,accounted for 75.6%of the total area of soil salinization,soil with the principal component and correlation analysis showed that salt ions,K⁺+Na⁺,Ca²⁺,Cl^-and SO₄^2-a major decisive role in the soil salt accumulation.Soil salinization is mainly controlled by the groundwater level,and also affected by the cultivated land reclamation period and planting type,Break up more than 30years of land soil profile 0-0.2m,0.6-0.8m,1.3-1.5m salt content is 4181 mg/kg respectively,3782 mg/kg and 2749 mg/kg,open less than 10 years of land soil profile corresponding horizon salt content is 4264 mg/kg respectively,6029 mg/kg and 7077 mg/kg,the two large difference,and the change trend,on the other hand,shows that cultivated fixed number of year can effectively reduce the soil salt content,and the salt through underground erosion;The salt content in soil profile of cultivated land planted with cotton,date tree and fruit tree were:(0-0.2m)5929 mg/kg,5192 mg/kg,4312 mg/kg,(0.6-0.8m)2814 mg/kg,3264mg/kg,3216 mg/kg,(1.3-1.5m)2594 mg/kg,3801mg/kg,3852 mg/kg,respectively.3.The mechanism of soil salinization under flood irrigation and interridge drip irrigation was revealed.The relationship between soil evaporation and the buried depth of groundwater level is an exponential decreasing function.The ultimate evaporation depth of sandy soil in the alluvial plain is about 2.95m and increases with the decrease of soil permeability coefficient.Drip irrigation in the study area is not high underground water level,but has formed the vadose water circulation system,the cultivated land ridges salt under the condition of drip irrigation with water to move away from the area of drip irrigation belt,stop the drip irrigation of houlong between salt and returned to the plant roots and the long-term vadose water evaporation and concentration effect cause soil salinization,microcirculation and severe local area jujube death arising phenomena have been found.4.Put forward the prevention and control countermeasures of soil salinization based on genetic mechanism.The comprehensive prevention and control measures based on the formation mechanism include the macro-control of regional groundwater,the large-scale digging and drainage ditch and the combination of irrigation and planting between ridges.