Wood ash is a high-quality potassium fertilizer; pay attention to these issues when collecting and applying it

Wood ash is the residue left after burning plant materials such as crop straw and dead branches and fallen leaves. According to rough estimates, the ash from burning plants in China each year exceeds 20 million tons. If calculated at an average of 5% potassium oxide, this is about 1 million tons, equivalent to 2 million tons of potassium sulfate. Under the condition of insufficient commercial potassium fertilizer in China, this is an important potassium fertilizer resource. Why is wood ash a good potassium fertilizer? What issues should be noted when collecting and applying it? 

The composition of wood ash is very complex. Its main component is potassium carbonate, and it generally contains 5%-10% potassium (K2O). It is easily soluble in water and is a quick-acting potassium fertilizer.

Three points should be noted when collecting and applying wood ash:

(1) Wood ash is alkaline and must not be stored or applied together with ammonium nitrogen fertilizers, nor added to human feces and urine, so as to avoid nitrogen volatilization loss. Wood ash should also not be piled in the open, to prevent potassium from being leached by rainwater;

(2) Wood ash can be used on neutral and calcareous soils, and is especially suitable on acidic soils, but it is not suitable for saline-alkali soil. When planting potatoes, cut the seed tubers and first mix them with wood ash, then plant them. This is a good, economical and effective way to apply wood ash, and it also has the effect of preventing insects and sterilizing;

(3) Pay attention to the application method. Wood ash can be used as a base fertilizer or topdressing fertilizer, and is most suitable as a seed-covering fertilizer for rice and vegetable seedbeds, because it can both provide nutrients and loosen the soil and raise soil temperature.