【作者】 段文典；

【导师】 张新民；

【作者基本信息】 甘肃农业大学 ， 农业水土工程， 2007， 硕士

【摘要】 提高现有土地生产能力,改良与开发利用盐碱化土地以及防治土壤的次生盐碱化,已成为实现土地资源可持续利用和农业可持续发展的一个重要方面。本文结合国家“九五”重点水利建设项目—甘肃河西走廊(疏勒河)农业灌溉暨移民安置综合开发项目的建设实际,根据灌区盐碱地改良分区选择典型改良区,开展了均质土壤大定额竖直压盐与粘土夹层土壤竖孔排盐两种代表措施的试验研究。通过对试验结果分析,提出了均质土壤大定额竖直压盐的排盐系数地区经验公式、洗盐定额计算方法,制定了洗盐制度;研究了有粘土夹层土壤的洗盐效率,分析了脱盐层厚度、计划脱盐层脱盐效率,提出了脱盐层厚度曲线、脱盐效率曲线和有效脱盐半径的概念,设计出了粘土夹层土壤竖孔排盐的排盐孔布置形式、排盐孔个数、洗盐定额、洗盐制度等技术参数。成果可用于指导灌区的盐碱地改良工作。(1)大定额灌水竖直压盐时,主级土壤(0～100cm)的排盐系数与含盐量呈线性关系,以此建立的地区冲洗定额经验公式也符合对数函数形式。(2)大定额灌水竖直压盐改良措施可取得良好的洗盐效果,冲洗定额可在4500m~3/hm~2至10500m~3/hm~2之间采用,连续或分次灌水,分次灌水时灌水定额1500～3000m~3/hm~2,第1次定额取较大值,每次灌水时间间隔以田面水落干后灌下次水为控制标准。(3)含粘土夹层土壤建立排盐竖孔以后,田内各点的脱盐效果与距离排盐孔的距离有关,且存在一临界距离,即有效脱盐控制半径。(4)高位粘土夹层土壤采用竖孔冲洗排盐的方法可取得良好的洗盐效果,排盐孔布置可选择每亩1、4、9、16孔的布置形式(层位越高,孔数越多),冲洗灌水定额可采用1500～3000m~3/hm~2,每次灌水后间歇2～3天,对应的排盐孔总面积应大于1.25～3.73m~2。更多还原

【Abstract】 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.更多还原