Ecological aspects of peat, straw, and wood ash application for energy willow cultivation

The utilization of ash obtained as a result of the combustion of fossil fuels (coal, peat) or biomass (straw, wood, solid waste) is an environmental problem that should be optimally solved. The chemical characteristics of ash depend on several factors, mostly on sources of fuel. According to characteristics, ash can be used in agriculture, forestry, or utilized for other purposes. The content of heavy metals (Cd, Ni, Pb, Cr) in peat ash is several times higher than in willow wood ash and straw ash. It means that peat ash application is limited to agricultural crops and its optimal application is one year before planting SRC trees, especially on poor and acid soils. The application of peat ash at a dose of 10 mg dry mass ha-1 in willow plantations on post-mining peaty soils changed soil acidity from 5.2 pH to 5.88 pH and stimulated tree growth. Wood and straw ash was applied to wil­low plantations on arable loam-sandy soils in doses 0.5, 1.0, and 1.5 t dry mass ha-1. The positive effect of ash application in doses 1.0 and 1.5 t dry mass ha-1 showed in the second year after the application both for soil and for willow growth.