Is wood ash potassium carbonate? Analysis of the main components of inorganic farmyard manure

The residue left after plants (herbaceous and woody plants) are burned is called wood ash. It is an insoluble substance and a type of inorganic farmyard manure. So what are the main components of wood ash? According to Xiao Jianchun, a large-scale sweet potato grower in Hunan, wood ash is the ash left after plants are burned, so wood ash contains almost all the mineral elements contained in plants. Wood ash is light and alkaline; when dry it is easily carried away by the wind, and when wet it is easily carried away by water, and contact with nitrogen fertilizer easily causes volatilization loss of nitrogen.

Master Xiao's second son, Xiao Feiyue, is a science student, and he put it more professionally: the main component of wood ash is potassium carbonate, with a relative molecular mass of 138. Because wood ash fertilizer comes from the ash left after plants are burned, wood ash contains almost all the mineral elements contained in plants. The most abundant is potassium, generally containing 6-12% potassium, of which more than 90% is water-soluble and exists in the form of carbonate; next is phosphorus, generally containing 1.5-3%; it also contains calcium, magnesium, silicon, sulfur and trace nutrient elements such as iron, manganese, copper, zinc, boron and molybdenum. The ash of different plants has different nutrient contents, and the potassium content of sunflower straw is the highest. When wood ash is applied at an equal potassium rate, its fertilizer efficiency is better than that of chemical potassium fertilizer. Therefore, it is an inorganic farmyard manure with wide sources, low cost, complete nutrients and obvious fertilizer efficiency.

Wood ash is light and alkaline; when dry it is easily carried away by the wind, and when wet it is easily carried away by water, and contact with nitrogen fertilizer easily causes volatilization loss of nitrogen. Therefore, the following methods should be adopted to accumulate wood ash:

Appendix: How should wood ash be stored?

1. Warehouse storage

Farmers with the means should build a permanent wood ash warehouse and pour the ash into it every day so that it can be accumulated. The ash warehouse should have a rain shelter, a raised floor (to avoid standing water), a hardened surface and moisture protection.

2. Bag storage

If possible, put the wood ash into plastic bags promptly and store it sealed.

3. Separate storage

Strictly avoid piling it together with other farmyard manure. Some farmers are accustomed to dumping wood ash into cesspits and composting it together with organic fertilizer, straw, etc., and others use wood ash as toilet bedding or pile it together with human excrement and urine or barnyard manure. This is very wrong. Because wood ash is alkaline, the results of the above practices will cause the volatilization of nitrogen in the organic fertilizer and reduce fertilizer efficiency. Handling wood ash in this way not only causes waste of fertilizer but also pollutes the environment.