灌溉水盐分组成对土壤水盐迁移参数的影响

发布时间：2018-07-25 15:13

【摘要】：淡水资源不足和盐渍化是干旱地区农业生产的限制因子。研究水盐迁移参数是水盐调控的重要目标。为此,该研究以甘肃省秦安县兴国镇果园土样为研究对象,采用水平土柱入渗法,探讨不同盐溶液(氯化钠、氯化钠和氯化镁、氯化钠和氯化钙、氯化钠和氯化钾)在矿化度均为3 g/L的条件下对土壤水分扩散率和盐分离子水平迁移的影响。结果表明:不同盐分组成的灌溉水质和含水率对土壤水分扩散率的影响均达极显著水平(P0.01)。在灌溉水矿化度均为3 g/L的条件下,氯化钠盐溶液传输水分的潜在能力最大,加入一定的复盐对水分的传导起到阻滞作用,阻滞能力的大小是:氯化钙氯化钾氯化镁。不同盐分组成的灌溉水对土壤碳酸氢根和硫酸根的水平迁移具有显著的影响(P0.05),对盐分、钙离子和钠离子水平迁移具有极显著的影响(P0.01)。入渗距离对土壤pH的影响以及灌溉水盐分组成对土壤钠吸附比的影响均达显著水平(P0.05)。灌溉水盐分组成对模型参数初始值和终止值有显著的影响,参数初始值和终止值均呈现:氯化钠氯化钠和氯化镁氯化钠和氯化钾氯化钠和氯化钙。因此,从微咸水利用和盐渍化土壤改良的角度考虑,在微咸水灌溉中加入一定量的钙制剂可抑制水分扩散和降低土壤盐分含量;从灌溉方法来看,需从地块的两端轮换灌溉可预防地块一端脱盐而另一端积盐的现象。这一研究结果对于指导干旱、半干旱地区微咸水利用具有重要的科学意义。
[Abstract]:Shortage of fresh water resources and salinization are the limiting factors of agricultural production in arid areas. To study the parameters of water salt migration is an important target of water salt regulation. Therefore, taking the soil samples from the orchard of Xingguozhen, Qinan County, Gansu Province as the research object, using the horizontal soil column infiltration method, the different salt solutions (sodium chloride, sodium chloride and magnesium chloride, sodium chloride and calcium chloride) were studied. The effects of sodium chloride and potassium chloride on the soil water diffusivity and the horizontal migration of salt ions under the condition of 3 g / L salinity. The results showed that the effect of irrigation water quality and moisture content of different salt composition on soil water diffusivity was very significant (P0.01). Under the condition that the salinity of irrigation water is 3 g / L, the potential capacity of sodium chloride solution to transfer water is the greatest. Adding a certain amount of double salt has a blocking effect on water conduction, and the blocking capacity is as follows: calcium chloride, potassium chloride, magnesium chloride. Irrigation water with different salt composition had significant effects on the horizontal migration of soil bicarbonate and sulfate (P0.05), and on the horizontal migration of salt, calcium and sodium ions (P0.01). The effect of infiltration distance on soil pH and the effect of salt composition of irrigation water on sodium-adsorption ratio were significant (P0.05). The salt composition of irrigation water has a significant effect on the initial values and terminations of the model parameters. The initial values and terminations of the parameters are: sodium chloride, magnesium chloride, sodium chloride, potassium chloride, sodium chloride and calcium chloride. Therefore, considering the use of brackish water and the improvement of salinized soil, adding a certain amount of calcium in brackish water irrigation can inhibit the water diffusion and reduce the soil salt content. Alternate irrigation from both ends of the plot can prevent desalination at one end and salt accumulation at the other. The results of this study are of great scientific significance to guide the utilization of brackish water in arid and semi-arid areas.
【作者单位】：甘肃省农业科学院土壤肥料与节水农业研究所;农业部甘肃耕地保育与农业环境科学观测实验站;中国农业大学资源与环境学院;甘肃农业大学草业学院;
【基金】：国家自然科学基金项目(41363004) 甘肃省农业科学院科技创新工程学科团队(2015GAAS03)
【分类号】：S278

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