Coal contains a certain amount of calcium, potassium, silicon and other elements before burning. These elements will not disappear after burning. Therefore, the ash after burning coal actually has a certain fertility, but the effective element content is very small. So can coal ash be used as fertilizer?

Coal is actually formed by the chemical reaction of some plant trunks after hundreds of millions of years of evolution after being buried in the ground. The amount of calcium, potassium and other elements in the coal ash after coal combustion is very small, which does not increase the fertility of the soil too much, and some coal also contains heavy metals, etc. Therefore, the burned coal ash is not recommended to be directly used as fertilizer. But this is not to say that coal ash cannot be used as fertilizer at all, it can be fermented with other manure to increase soil fertility. 

The ash from the burning of coal has a certain adsorption effect and can be piled up with cow, sheep, pig, chicken manure and straw for high-temperature fermentation to form a decomposed farmhouse organic fertilizer. Some trace elements contained in coal ash can be mixed with organic fertilizer to increase the fertilizer efficiency of organic fertilizer. It can be used as a base fertilizer and top dressing to promote the healthy growth of crops and has a certain yield increase effect on some cereal crops.

Coal ash can also be used to improve hardened soil and neutralize acid soil. Adding some coal ash to the compacted soil can improve the soil compaction, which is conducive to retaining water and fertilizer. So when making flower soil, some coal ash will be added to increase the air permeability of the soil, but the amount should not be too much, too much will easily lead to the loss of fertilizer and water, which is not conducive to plant growth. Because coal ash contains calcium oxide, it can neutralize acidic soil, improve the acidity and alkalinity of the soil, and help restore the soil and soil environment.

The coal ash after coal combustion needs to be treated before use. One of the treatment methods is to soak the coal ash in water for a period of time, then drain the water and dry it before use. Generally speaking, the content of effective elements in coal ash is not high, so it is not recommended to use it directly as a fertilizer. It is recommended to mix it with other fertilizers and pay attention to the mixing ratio.