Abstract:

To strengthen resource utilization of coal-based solid waste in northern Shaanxi and to improve the ecological environment of local saline and alkaline soils, this experiment used fly ash, desulfurization gypsum, wood vinegar liquid, biochemical xanthate and sheep dung materials compounded with different conditioning agents to comprehensively improve the saline and alkaline soils in northern Shaanxi. A greenhouse pot experiment was conducted to analyze the effects of compound of different conditioning materials on soil pH, chemical properties and growth of tall fescue. The results showed that: (1) soil pH decreased significantly after compound treatment of different conditioning materials by 0.52-0.64 units, and total soil alkalinity decreased significantly compared with the control by 20%-52.5%; (2) soil organic matter, alkaline-dissolved nitrogen, quick-acting potassium, and effective phosphorus contents increased after compound treatment of different conditioning materials by 1.07-5.09, 1.32-4.44, 3.43-19.13, 2.67-27.42 times, respectively; (3) tall fescue plant height increased by 17.54%-38.86%, stem thickness increased by 10.71%-27.27%, leaf length increased by 12.17%-43.10%, leaf width increased by 21.16%-43.11%, aboveground dry weight increased by 176.02%-280.12%, belowground dry weight increased by 53.01%-171.08%. Through the comprehensive evaluation of the principal component analysis, the comprehensive evaluation of solid waste conditioner in this experiment was higher than the control. When the conditioner application rate was 20%, it could not only ecologically utilize solid waste, but also significantly improve the saline-alkali soil in northern Shaanxi and promote the growth of tall fescue.

Key words: solid waste, saline soils, compound conditioner, chemical properties, tall fescue