# Application of Fly Ash Obtained from the Incineration of Municipal Solid Waste in Agriculture
## 8 Conclusions  
Adding fly ash to soil in different concentrations improves the physical, chemical, and biological properties of soil; improves soil quality, porosity, soil texture; helps plant growth; reduces soil bulk density; improves water retention capacity; optimizes the pH value; improves soil aeration; reduces crust formation provides micronutrients such as Fe, Zn, Cu, Mo, B, Mn, K, P, Ca, Mg, and S; and it works as a partial substitute for lime to restore alkaline soil.  
Due to the addition of fly ash to sandy soils, the production of clover, rye, barley, rapeseed, rice, soybeans, sunflower, wheat, tomatoes, and carrots increased.  
The use of fly ash in agriculture is 1.38 billion tons, with up to 0.63% of all fly ash generated.  
Soils that were mixed with up to 50% fly ash had lower bulk density and higher water holding capacity due to structural and textural changes. Soil water holding capacity is related to surface area, pore space volume, and pore space continuity. The hydraulic conductivity is lower than that of the plain soil, but the porosity and workability of the soil are better. The application of high rates of fly ash changed the texture of sandy and loamy soil. The analysis of the soil to which different concentrations of ash were added revealed an increase in the potassium and the phosphorus content of the soil, and the following microelements, manganese, calcium, nickel, copper, and zinc, had progressive increases with the increase in the concentration of added ash. Water holding capacity and plant production were improved, and the acidity of clay-sand soil was reduced by adding 200-400 t/ha of fly ash. Plants had an improvement in growth in the fly ash added to soil; soil nutrient mobility increased; and chemical and physical properties were improved by applying the following amounts of fly ash: 0, 25, 75, and 100 tons/ha.  
The use of fly ash in agriculture is profitable, and economically, 10 million hectares of land out of 150 million hectares of cultivated land can be safely occupied for fly ash application per year. At a fly ash dose of 20 mt per hectare, 200 million tons of fly ash would be consumed per year. Fields treated with fly ash would provide an additional yield of 5 million tons of grain per year.  
Considering the increase in the amount of municipal solid waste and climate change, we believe that by incinerating this waste we reduce its volume, protect the environment, and it can be used as a fertilizer for degraded soils, which favors plant development and helps the soil. This is the municipal solid waste management method. We have also presented the methods of treating the ash obtained from the incineration of municipal solid waste, so that if the ash contains heavy metals or salts by treating the ash, it can be used as a soil fertilizer.  
The effects of applying certain concentrations of ash on different types of soil over long periods of time must be analyzed.  
Conceptualization: C.O.R.; methodology: C.O.R. investigation: C.O.R. and M.R.; resources: C.O.R. and M.R.; writing--review and editing: C.O.R. and M.R. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The authors declare no conflict of interest.