高硫煤矸石对苏打盐化土改良效果的研究

发布时间：2018-11-24 08:59

【摘要】：土壤盐碱化和次生盐碱化问题在世界范围内广泛存在,特别是干旱、半干旱地区,问题更为严重。山西省共有盐渍土30.13万hm2,其中70%分布在大同盆地。本文针对山西大同盆地苏打盐化土分布较广、危害严重、治理难度较大的现状,选取山西省储量丰富的高硫煤矸石为改良材料,通过室内培养试验和原状土柱模拟试验,分析土壤的物理、化学指标,以及植物的生长,盐分,酶活性指标,探索高硫煤矸石对苏打盐化土的改良效果,确定高硫煤矸石在大同盆地改良苏打盐化土的最佳粒径和用量,旨在为我国的内陆苏打盐化土化学改良方面提供理论依据。主要研究结果如下:(1)通过在恒温人工气候箱中将各4种不同细度和用量的高硫煤矸石与苏打盐化土在湿润的环境中进行混合培养。研究结果表明添加高硫煤矸石可明显改善苏打盐化土的化学性状,显著降低土壤的pH、ESP、水溶性Na+含量,虽然增加了土壤中盐分离子含量,但是产生毒害作用的钠离子含量降低了。其中,当用量为32g/kg(煤矸石/土)、细度为70目的高硫煤矸石对苏打盐化土的效果最佳,相对于原始土来说,土壤的pH值降低了10.24%,ESP值降低了68.24%,交换性Na+降低了35.12%,EC值增加了46.30%。(2)通过土柱淋溶试验可知:土壤淋洗液中的pH随高硫煤矸石用量的增加逐渐降低,受淋洗次数的影响较小。EC和水溶性钠离子变化趋势较为一致,与高硫煤矸石用量呈正相关,与淋洗次数呈负相关。(3)高硫煤矸石和纯水淋洗的共同作用下,处理为32 g/kg对0-20 cm表层土壤的理化性状影响效果最好。与CK相比:土壤容重降低了5.09%,土壤总孔隙度增加了34.27%,土壤pH降低了11.07%,ESP降低了85.33%,土壤EC值较原始土有所增加,但与对照相比没有显著性差异,土壤中的水溶性Na+含量最低,为0.11 cmol/kg;CO32-含量未检测到;高硫煤矸石用量为48 g/kg时,土壤中的Ca2+含量显著高于其他处理,其次为处理32 g/kg;各处理中SO42-与对照相比,变化不明显,仍有缓慢下降的趋势。(4)高硫煤矸石可促进柳枝稷的生长发育,用量为32 g/kg时,出苗率为66.17%,植株的株高为54.67 cm,植株的干鲜重、根系干鲜重达到最大值;植株的K/Na比最大,为1.83;植物体中的两种酶活性最大,相对于对照分别增加了225.87%和20.07%。
[Abstract]:The problems of soil salinization and secondary salinization are widespread all over the world, especially in arid and semi-arid areas. There are 301300 hm2, salinized soils in Shanxi Province, of which 70% are distributed in Datong Basin. In view of the fact that the soda-salinized soil in Datong Basin of Shanxi Province is widely distributed, seriously harmful and difficult to manage, the rich high-sulfur coal gangue in Shanxi Province is selected as the improved material, and the indoor culture test and the undisturbed soil column simulation test are carried out. The physical and chemical indexes of soil, plant growth, salt content and enzyme activity index were analyzed. The improvement effect of high-sulfur coal gangue on soda-salinized soil was explored, and the optimum particle size and dosage of high-sulfur coal gangue in improving soda-salinized soil in Datong Basin were determined. The aim is to provide theoretical basis for chemical improvement of inland soda salinized soil in China. The main results are as follows: (1) four kinds of high-sulfur coal gangue with different fineness and dosage were mixed with soda-salinized soil in humid environment. The results showed that the addition of high-sulfur coal gangue could obviously improve the chemical properties of soda-salinized soil and decrease the content of pH,ESP, water-soluble Na in soil, although it increased the content of salt ion in soil. But the toxic sodium ion content decreased. When the dosage is 32g/kg (coal gangue / soil) and the fineness is 70 objectives, the effect of high-sulfur gangue on soda-salinized soil is the best. Compared with the original soil, the pH value of soil decreases 10.24% and 68.24%. The EC value of exchangeable Na decreased 35.12% and increased by 46.30%. (2) through soil column leaching experiment, the pH in soil eluate decreased gradually with the increase of the amount of high-sulfur coal gangue. The change trend of EC and water-soluble sodium ions was consistent, which was positively correlated with the amount of high-sulfur gangue and negatively correlated with the times of leaching. (3) under the combined action of high-sulfur coal gangue and pure water leaching, The effect of 32 g/kg treatment on the physical and chemical properties of topsoil was the best in 0-20 cm. Compared with CK, soil bulk density decreased 5.09%, soil total porosity increased 34.27%, soil pH decreased 11.07% and 85.33%, soil EC increased compared with original soil. But there was no significant difference compared with the control. The content of water-soluble Na in soil was the lowest (0.11 cmol/kg;). When the amount of high-sulfur gangue was 48 g/kg, the content of Ca2 in soil was significantly higher than that in other treatments, followed by the treatment of 32 g / kg. (4) High sulfur gangue can promote the growth and development of switchgrass. When the dosage is 32 g/kg, the seedling emergence rate is 66.177.The plant height is 54.67 cm,. The dry fresh weight of the plant and the dry fresh weight of the root reached the maximum value. The K/Na ratio of the plant was the largest (1.83), and the activity of two enzymes in the plant was the largest, which increased by 225.87% and 20.07%, respectively, compared with the control.
【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S156.4

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