Study On The Ratio Of Soil Improvement For Lettuce Planting With Coal Gangue As Substrate

The pile of coal gangue invaded a large amount of land,causing shortage of arable land near the mining area,environmental pollution and other problems,which seriously affected the sustainable development of society and economy.Therefore,the soil substrate of coal gangue hills was improved to make it suitable for crop growth.It is of great significance to solve problems such as insufficient agricultural land resources.Based on the experiment of potted planting lettuce with different ratios of coal gangue and fly ash and the experiment of planting lettuce with different particle size and gradation matrix of coal gangue,this paper analyzes the physical and chemical properties of different ratios of substrates and the growth status of lettuce,and selects suitable mining areas.The best substrate ratio for the soil substrate improvement of the gangue hill,and the preliminary design of the soil substrate improvement plan for the coal gangue hill flat panel area of Xiaonan Mine.Based on the basic physical and chemical properties of coal gangue and fly ash,the ratio of coal gangue and fly ash is 2:1,3:1,4:1,6:1,8:1,and 1:0 with a fixed amount of straw and soil.Formulated into a mixed matrix,the coal gangue is 8:1:1,1:1:1,2:1:2,2:2:1,1:3:1,1:1 according to fine particles,medium particles,and coarse particles.: 3 proportions and quantitative fly ash,straw,and soil are mixed into a mixed matrix,the difference in the properties of the two groups of soil mixed matrix with different proportions is explored,and the comprehensive index value of soil quality is calculated for the mixed matrix.The results show that the chemical properties and bulk density,field water holding capacity,porosity and other physical properties of the two groups of compound substrates are significantly improved compared with the properties of the control substrate,and they can reach the fertility level of fertile soil.The feasibility of improving the soil of coal gangue hills as agricultural land substrates.Plant lettuce in pots,measure and analyze the growth index of lettuce and the substrate property index after planting lettuce.From the aspects of lettuce emergence rate,plant height,stem thickness,etc.growth and the property changes of the substrate before and after planting,the different proportions of substrates are measured and analyzed.Comparative analysis shows that the best ratio of coal gangue to fly ash is 6:1;the best gradation ratio of fine particles,medium particles,and coarse particles of coal gangue is 1:1:3.It is concluded that the suitable ratio for improving the soil matrix of the gangue hills in the mining area is 42.9% coal gangue,7.1% fly ash,10% straw,and 40% soil.The gangue particle size ratio is 20% fine particles,20% medium particles and 60% coarse particles.The preliminary design of the soil substrate improvement plan for the coal gangue hill in Xiaonan mining area provides a scientific basis for the soil improvement of the gangue hill for agricultural land,which is conducive to the realization of the goal of green mining and sustainable development of the mine.