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宁夏南部气候干旱,广泛分布着底盐灰钙土和黑垆土,地下水位一般达20—30米以上。由于降雨量稀少,地表及地下淡水资源缺乏,而苦水资源丰富,苦水矿化度高达4—7克/升,多为钠质氯化物硫酸盐水.实践证明,苦水只要利用得当,就能使小麦或大麦获得高额产量。但苦水灌溉后易发生土壤次生盐渍化,这与水质及土壤质地有密切关系,轻壤土透水性良好,苦水灌溉后易将盐分淋洗排至深层,粘土透水性不良,因而不易将盐分淋洗排至深层,适宜苦水灌溉的理想土壤为轻、中壤土,长期灌溉仍能使土壤盐分含量维持在0.20%左右。为控制灌水定额必须划小地块,以0.5—0.7亩为宜。生育期灌水要掌握头水要饱,二水三水要紧跟上,使地面经常保持湿润,通过灌溉之后,可使表层积累的大量盐分,降低50—70%,不致危害作物生长;当作物成长起来,耐盐性增强,这就为丰收打下基础。其次为了控制土壤盐渍化的发展还可采用下面几种措施:1.种植绿肥作物及施用有机肥料;2.冬灌;3.洪漫;4.种植耐盐作物;5.深翻晒垡;6.利用钾钠离子平衡理论,控制钠害.这些措施必须相互配合,综合运用,才能达到抑盐助苗,以达到防治盐化的根本目的.
Ningxia southern climate arid, widely distributed at the end of the salt ash and black soil Clay, groundwater level generally up to 20-30 meters above. Due to scarce rainfall, the lack of surface and underground fresh water resources, and rich bitter water resources, bitter water salinity of 4-7 g / L, mostly sodium chloride sulfate water. Practice has proved that bitter water, as long as properly used, can make wheat Or barley for high yields. However, the secondary salinization of soil is easy to happen after bitter irrigation, which is closely related to water quality and soil texture. The permeability of light-loam soil is good. After irrigation with bitter-water, salt leaching is easy to drain to the deep layer, and clay is poor in water permeability, The leaching to the deep, the ideal soil for bitter water irrigation light, medium loam, long-term irrigation can still maintain the soil salinity content of about 0.20%. To control the irrigation quota must draw a small plot to 0.5-0.7 acres is appropriate. Growing water to master the head water to be full, the two water three water should be closely followed, so that the ground often keep moist, after irrigation, can make a lot of surface salt accumulation, reduce 50-70%, will not endanger the crop growth; when the crop Grow up, salt tolerance increased, which laid the foundation for the harvest. Second, in order to control the development of soil salinization, the following measures can be taken: 1. Planting green manure crops and applying organic fertilizers; 2. Winter irrigation; 3. Hung Man; 4. Planting salt-tolerant crops; The use of potassium and sodium ion balance theory to control sodium harm.These measures must be coordinated with each other, comprehensive use, in order to achieve salt help seedlings in order to achieve the fundamental purpose of prevention and treatment of salinization.