盐碱土施用硅钙渣对披碱草生长的影响及机制

盐碱土的改良和利用是人们关注的热点,脱硫石膏是常见的盐碱土改良剂之一.硅钙渣是粉煤灰提铝的副产物,富含钙和硅等有益于抗盐碱的元素,经烟气脱硫后性质与脱硫石膏相似,有应用于盐碱地改良的潜力.采用盆栽试验,探究盐碱土施用硅钙渣(硅钙渣施用量为0、10、25、50 g·kg-1,以50 g·kg-1脱硫石膏处理作为参照)对披...

Growth of Elymus nutans in saline saline-alkali soil amended with calcium silicate slag:Performance and mechanism

Saline-alkali soil management is an issue of worldwide concern.Desulfurization gypsum is one of the common saline soil amendments.Silica-calcium slag is a by-product of aluminum extraction from fly ash.It is rich in calcium,silicon and other elements,which enhance the saline-alkali resistance of plants.Therefore,silica-calcium slag has the potential to improve saline-alkali soil after flue gas desulfurization.Silica-calcium slag at 0,10,25 and 50 g·kg^-1 soil,and 50 g·kg^-1 soil desulfurization gypsum as a comparison were applied as treatments mixed into saline-alkali soil in pot experiments to explore the effects on the growth of Elymus nutans.It was found that silicacalcium slag improved the growth of E.nutans in saline-alkali soil.The weight per plant of E.nutans was increased by a factor of 0.4-1.6,the total plant biomass per pot was increased by a factor of 2.8-6.8,the root length by3.16%-40.21%and the plant height by 9.07%-17.35%after the application of silica-calcium.The treatment with 50 g·kg^-1 silica-calcium slag applied was the best.Moreover,the performance of 50 g·kg^-1 silica-calcium slag was also better than that of 50 g·kg^-1 soil desulfurization gypsum in plant growth.The possible mechanisms were as follows:1)Incorporating silica-calcium slag and desulfurized gypsum significantly reduced the soil pH,which could improve the physical and chemical properties of soil and alleviate the alkali stress to plants.2)Silica-calcium slag increased the absorption of Ca and Si by plants,which are beneficial for resisting salt and alkali stresses.3)Silicacalcium slag helped the plants to absorb more potassium and reject more sodium to improve the osmotic pressure of plant cells,increasing the intracellular K∶Na balance,thus reducing the harm from saline-alkali stress.This study shows that silica-calcium slag can effectively improve the properties of saline-alkali soil and promote the growth of E.nutans,providing a new option for the utilization of coal-based solid wastes and the improvement of saline-alkali soil in northern China.