The Experiment And Research On Improvement Technology Of Saline Land In Shulehe Irrigation Area

Improving productivity of the existing land,Improve and utilize the saline land and prevent secondary soil salinization.It has become an important aspect of the sustainable use of land resources and sustainable development of agriculture.This article unifies the 9^th five year state key construction plan for water conservancy project-Gansu Hexi Corridor(Shule River) the agricultural irrigation and the immigration placement comprehensive development project construction reality.According to the saline and alkaline land ameliorates divisional in Shule irrigation district of Gansu province,the saline and alkaline land ameliorates was studied with two methods that upright pressure salt with big irrigation quota under homogeneity soil(PS) and discharging salt with upright hole under clay interlayer soil(DS).The modulus area experience formula that applied to PS was brought forward.The method of calculating washing salt quota and washing salt system was worked out.Through studying on washing salt efficiency of clay interlayer soil,thickness of desalting tier,desalination efficiency of planning desalination tier,brought forward the concept of effective desalination radius,designed the clay parting soil vertical stroke hole drainage salt platoon salt hole arrangement form,the platoon salt hole integer,the fixed quantity of washing salt,washing salt technical parameter and so on.The achievement may use into instruct the irrigation area salt alkaloid to improve the work:(1) The vertical pressure salt of the great fixed quantity irrigation,basic shell soil (0～100cm) the platoon salt coefficient and the salt content assume the linear relations,also conforms to the logarithmic function form by this establishment local flushing fixed quantity empirical formula.(2) The vertical pressure salt improvement measure of the great fixed quantity irrigation is possible to obtain the good washing salt effect,the flushing fixed quantity may use in the 4500m³/hm²～10500m³/hm²,continues or irrigates at different times,irrigates at different times when the irrigation fixed quantity is 1500～3000m³/hm²,the 1st fixed quantity takes an greater quantity,the time-gap of irrigation each time will be after the field surface is dry as the the control standard of the next irrigation.(3) Containing the clay parting soil after establishing vertical hole of drainage salt,each desalinization effect in the field is related away from the distance with the drainage salty hole,also has a critical distance,namely effective desalinization control radius. (4) The top digit clay parting soil uses a vertical stroke hole as the method of flushing drainage salt is possible to obtain the good washing salt effect,the salty hole arrangement chooses arrangement forms(position is higher,hole are more)of each acre 1,4,9,16,the flushing irrigation fixed quantity is possible to use 1500～3000m³/hm²,the intermittent 2～3 days after irrigation for each time,the total area of corresponding platoon salt hole should be bigger than 1.25～3.73m².