关键词: 盐碱土, 炉渣, 煤矸石, 生物炭, 木醋液, 盐地碱蓬, 黄骅港

Abstract:

【Objective】 Soil salinization has an important effect on the plant growth. The area covered by salinized soil in China is increasing and needs to be treated urgently, so as to alleviate the increasing strain of land resources. Meanwhile, the amount of coal gangue and municipal solid waste incineration slag in China is huge, but their effective utilization rate is very low. In addition, thermal degradation has gradually become the main direction of agricultural and forestry waste resource utilization, producing a large amount of biochar and wood vinegar. In order to demonstrate the improvement effects of different solid waste products and their disposal byproducts on saline-alkali soil, soil improvement and pot experiments were conducted to promote the absorption of solid waste, and also to provide a support for the treatment of saline-alkali land in Huanghua Port. 【Method】The 10 treatments consisted of a control group (CK), slag and coal gangue (S10, S50 and S100), biochar (C10, C50 and C100), and wood vinegar (V300, V100 and V50) were applied in this study. S10, S50 and S100 were respectively treated by adding 10 g, 50 g and 100 g mixture of 50% slag and 50% coal gangue. C10, C50, C100 were respectively treated by adding 10 g, 50 g and 100 g of biochar. The V300, V100 and V50 were treated by adding 500 mL of wood vinegar which was diluted 300, 100, and 50 times, respectively. The effects of each treatment on soil saline-alkali properties, nutrient contents and agronomic characteristics of Suaeda salsa were analyzed by determining pH, total soluble salt, exchangeable sodium, cation exchange capacity, alkalinity, organic matter, available nitrogen, available phosphorus, available potassium, germination potential, germination rate, germination index, and biomass. 【Result】All treatments could reduce pH, total soluble salt and exchange sodium percentage of the original soil samples while increasing soil nutrient contents and promoting the growth of Suaeda salsa, but differences were observed among different treatments (P < 0.05). Wood vinegar showed the best improvement effect on the soil saline-alkali condition. For example, V300 had the lowest pH, total soluble salt, exchangeable sodium, and alkalinity but its soil nutrient condition and growth of Suaeda salsa were poor. On the contrary, although slag and coal gangue had the worst effects on soil saline-alkali properties, organic matter of S10, S50 and S100 was significantly higher than that of other treatments (P < 0.05). Meanwhile, Suaeda salsa plants in soils that received slag and coal gangue grew better. The organic matter, germination rate, germination index and biomass of Suaeda salsa of S50 were 13.05 g/kg, 80.40%, 47.75% and 99.56 g, respectively, which were significantly higher than those of the other treatments (P < 0.05).The improvement effects of biochar on the soil saline-alkali properties, nutrient content, and agronomic characteristics of Suaeda salsa were average. 【Conclusion】 Slag and coal gangue, wood vinegar, and charcoal powder all could reduce salt and alkali contents, improve soil nutrient contents, promote seed germination, and plant growth of Suaeda salsa. Moreover, the effect of S50 on soil nutrient contents and agronomic characteristics of Suaeda salsa was the best and can be used as the saline-alkali soil improvement material in Huanghua Port.

Key words: saline-alkali soil, slag, coal gangue, biochar, wood vinegar, Suaeda salsa, Huanghua Port