Conservation of resources and CO${}_2$ savings - recycling fertilizer using wood ashes

The usability of rust and boiler ash from the combustion of natural wood as a fertilizer/starting material results from its contents of calcium, potassium, phosphorus and magnesium. Since these nutrients are otherwise mined, sometimes far from the point of use, resource conservation and CO${}_2$ savings can be beneficial for ash-based fertilizers. The nutrients calcium and potassium are already spontaneously soluble in water. Compliance with the pollutant limit values in accordance with the Fertilizers Ordinance must be observed. In conjunction with compost or fermentation product there ist the possibility of producing organic-mineral P/K fertilizers.