Nutrient Release Characteristics Of Coal-based Compound Fertilizers And Soil And Crop Effects

China’s coal mine waste stock is huge and increasing year after year,causing great harm to the environment and human beings.The utilization of coal mine waste is imminent.The purpose of this study is to explore the resource utilization of coal mine waste in the agricultural direction.The test uses coal mine weathered coal,slime,coal gangue and common fertilizer as raw materials to prepare coal-based compound fertilizers.The nutrient release effect of the water immersion test and soil column leaching test is used to screen coal-based compound fertilizers of different proportions.,And taking forage oats as the research object,to study the effects of applying coal-based compound fertilizers with different nutrients on soil nutrients,soil organic matter,soil enzyme activity,oat growth and development,yield and fertilizer nutrient utilization,and explore the use of coal-based waste The feasibility of material production of organic and inorganic compound fertilizers.The main findings are:(1)The delay effect of weathered coal,slime and gangue on the release of nutrients from coal mine wastes is shown as weathered coal>slime>gangue.(2)Under the condition of the same fertilization level,compared with ordinary chemical fertilizer(HF)treatment,20%nutrient added coal-based compound fertilizer(MJF1),25%nutrient added coal-based compound fertilizer(MJF2),30%nutrient added The cumulative leaching rate of the coal-based compound fertilizer(MJF3)was significantly reduced(p<0.05),in which the ammonium nitrogen decreased by 19.13%,22.91%,17.45%,nitrate nitrogen decreased by 10.73%,13.84%,17.12%,water-soluble phosphorus decreased by 27.53%,22,86%,25.06%,water-soluble potassium decreased by 34.81%,27.99%,21.84%respectively;changing the proportion of added coal-based substances will not mix coal-based The dynamic change law of nutrient accumulation leaching rate of ammonium nitrogen,water-soluble phosphorus and water-soluble potassium in fertilizer has obvious influence,but it has obvious influence on the dynamic change law of nutrient accumulation leaching rate of nitrate nitrogen.(3)The application of coal-based compound fertilizer added with a certain proportion of coal-based materials can effectively increase the content of alkali-decomposed nitrogen,available phosphorus,available potassium and organic matter in the soil.Compared with HF treatment,MJF3 treatment had the most significant effect during the harvest period,and the soil alkaline nitrogen content increased by 48.57%;MJF2 treatment soil available phosphorus content increased by 28.06%,the most significant effect;MJF3 treatment soil available potassium content increased by 70.98%,The effect is the most significant;the organic matter content of the soil treated with MJF1 is increased by 25.16%,the effect is the most significant;the application of coal-based compound fertilizer can significantly reduce the soil pH,compared with HF by 0.60～0.64 unit.(4)Applying coal-based compound fertilizer with a certain percentage of coal-based materials can significantly increase soil enzyme activity.Compared with HF treatment during harvest,MJF2 treatment soil urease activity increased by 13.64%,the most significant effect;MJF3 treatment soil catalase activity increased by 10.28%,the most significant effect;MJF1 treatment soil invertase activity increased by 6.52%,the effect The most significant;changing the addition ratio of coal-based materials in coal-based compound fertilizers will not significantly affect its effect on soil urease,catalase,and sucrase activities.(5)Compared with HF treatment during the harvest period,MJF2 treatment can effectively promote the growth and development of oat plants,plant height increased by 2.12%,MJF1 inhibited the promotion of fertilizer nutrients on plant height,decreased by 5.35%;HF treatment,each coal-based fertilizer treatment did not significantly promote plant stem diameter;compared with HF treatment,MJF2 and MJF3 treatments increased the leaf chlorophyll content of the plants during the harvest period by 3.88%and 2.52%,and MJF1 treatment decreased 6.85%;The yield of oat hay treated was 11731.22kg/hm2,11688.29 kg/hm2,which was 4.23%and 3.85%higher than that of HF treatment.The yield of hay treated with MJF1 was 10535.20 kg/hm2,which was reduced by 6.39%.The utilization rate of nutrients increased by 7.97%,6.94%,12.3%and 7.06%,6.70%and 11.86%respectively,and the utilization rate of nitrogen,phosphorus and potassium nutrients by MJF1 treatment decreased by 3.8%and 3.94 respectively%,6.35%.In summary,the coal-based compound fertilizer has a certain slow-release effect on fertilizer nutrients;the application of the coal-based compound fertilizer effectively improves the content of soil organic matter,alkali-decomposed nitrogen,available phosphorus,available potassium,and improves soil urease and peroxidation Hydrogenase and sucrase activities extend the fertilizer efficiency and lower the soil pH;the application of coal-based compound fertilizers(MJF2 and MJF3)added with an appropriate amount of coal-based materials can effectively promote the growth and development of oat plants,improve crop yield and fertilizer nutrients Utilization rate,but excessive addition of coal-based compound fertilizer(MJF1)will inhibit the fertilizer effficiency.Therefore,it is feasible to use appropriate amount of coal-based waste to prepare coal-based compound fertilizer.