Wood ash has long been used as a source of calcium, potassium and other nutrients. Although the chemical characteristics of wood ash can vary considerably, the average fertilizer value would be about 0% nitrogen, 1% phosphorus, and 3% potassium. Many wood ashes can also be used as a liming agent to raise the soil pH. Its liming effect ranges form 8 to 90% of the neutralizing power of lime.
There are many studies that have shown the safety of the beneficial reuse of wood ash on agricultural lands. Wood ash contains few elements that can pose environmental problems and the metal content is typically low. Some studies indicate wood ash can increase plant growth up to 45% over traditional limestone.
The Georgia Department of Agriculture and Environmental Protection Division have worked with the University of Georgia Cooperative Extension Service to develop best management practices for the use of wood ash as a soil amendment. Details of these best management practices can be found in publications in our Resources section.