利用SAR和pH分析脱硫石膏改良碱(化) 土壤的机理

通过对碱土和强碱化2种土壤施加不同数量脱硫石膏进行改良的大田试验研究,探讨了土壤N a+吸附比SAR以及土壤溶液pH值的变化规律。研究结果表明:经过1年的大田试验后,2种土壤的在(0~15 cm的SAR以及pH值较对照均有了明显的降低,且不同处理的试验效果差异较大。1年的大田试验对15 cm以下土层的pH值影响甚微。这说明经过1年的大田试验后,根区活动层范围内的土壤钠碱化度明显降低,土壤理化性质在一定程度得到了改善。由于供试土壤的渗透性较差,经过N a+-C a2+交换后,0~15 cm土乘代换出的盐分不能全部被淋洗排出土体,在土体下层附集,这无疑说明了碱土改良是一个较漫长的过程。在改良的初始阶段,强度碱化土壤的改良效果要优于碱土区的改良效果,这是由土壤原有的碱化程度以及土壤的理化性质决定的。

The Mecganism on Sodic Soils Throwed Desulfurized Gypsum was Analyzed from SAR and pH

The fact that different amount of desulfurized gypsum was used in sodic soil and strongly alkali soil was studied in the paper. The laws of the change of SAR (sodic absorption ratio) on both kinds of land and the change of pH in soil solution were studied. As it was turned out, the vale of SAR and Ph on amended soil was less than that of virgin soil. Meanwhile, the vale of SAR and pH changed greatly in different treatments. After a year, in which, sodic soil and strongly alkali soil were suffered by that desulfurized gypsum was used and the water was penetrated , the vale of SAR of sodic soil and strongly alkali soil which depth were more than 15 cm varied litter more, but the vale of pH didn't almost vary at all. This indicated that exchangeable sodium percentage (ESP) of sodic soil and strongly alkali soil was reduced, physical and chemic characters of that were improved in the 15 cm depth of soil. For the reason of the ability of infiltration is very poor in sodic soil and strongly alkali soil, the saline which was leached from 15 cm depth of sodic soil and strongly alkali soil was not excluded form the body of soil in all, the rest was remained in the soil body. It is not surprising that the time is very long before sodic soil and strongly alkali soil are improved in every inch in physical and chemic characters. As the case maybe, the result of mend for strongly alkali soil on the commence is better than that of sodic soil for the fact that initial character of physics and chemistry is difference between sodic soil and strongly alkali soil in essence.