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下野地灌区位于天山北麓,玛纳斯河中下游的广阔冲积-洪积平原上,由于古代及现代土壤积盐和脱盐过程,土壤普遍盐化碱化.碱化土和龟裂碱土面积达64—71%.碱化度15—20%,高者大于50%,有机质小于1%,总盐量0.2—1.2%,pH8.5—9.6,透水性极差,每昼夜仅3—13厘米,湿时泥泞,干时板结.因此,极大地妨碍了农业生产的进一步提高.灌区盐碱土的不良性质具体表现在“盐、碱、水、肥、气”五个方面.荒地开发初期须以水治盐(压盐、排水洗盐),为作物生长及进行生物改良奠定基础.改良利用盐碱土还必须以改善土壤水、肥条件,克服其不良性质为中心.几年来实践证明,苜蓿(紫花苜蓿,下同)栽培是改土培肥的一项重要措施,在新疆生产建设兵团大农业经营的条件下,苜蓿又是以轮作、耕作、灌溉、施肥等措施组成的综合措施体系中的中心环节.
The lower reaches of the irrigation area is located in the northern Tianshan Mountains, the Mannusi River in the vast alluvial-alluvial plain, as a result of ancient and modern soil salt accumulation and desalination process, the soil generally salinization alkalization soil and cracked alkaline earth area of 64 -71%, basification 15-20%, higher than 50%, organic matter less than 1%, total salt 0.2-1.2%, pH 8.5-9.6, very poor water permeability, only 3-13 cm per day and night, Wet muddy, dry compaction, therefore, greatly hindered the further improvement of agricultural production.The irrational nature of saline-alkali soil in irrigation area is manifested in the five aspects of “salt, alkali, water, fertilizer, gas.” Salt treatment (pressure salt, drainage salt washing), for the growth of crops and biological improvement lay the foundation for the improvement of the use of saline-alkali soil must also be to improve soil water and fertilizer conditions, to overcome its bad nature as the center.Over the years proved that alfalfa Alfalfa, the same below) cultivation is an important measure to improve soil fertility. Under the condition of large-scale farming operation of Xinjiang Production and Construction Corps, alfalfa is also the center of a comprehensive system of measures consisting of rotation, tillage, irrigation and fertilization Links.