Willow wood production on radionuclide polluted areas

One of the key environmental problems in Belarus is effective use of agricultural lands contaminated by radionuclide due to the Chernobyl disaster. The alternative method to traditional agricultural crops is fast growing willow cultivation. It is possible to use biomass of willow as renewable energy source. The goal of our investigation was the estimation of environmental aspects of willow wood production on polluted areas. The field study experiments (2007-2010) were conducted at Krichev district of Mogilev region in eastern Belarus. This region characterized by high level of Cs-137 contamination as well as high level of heavy metals pollution. In the first stage of experiments, the concentration of cesium-137 in different parts of willow biomass had been measured and transfer factor calculated. The measuring had been done for leaves, roots, and wood. To control cesium-137 accumulation in willow biomass we apply different types (nitrogen N, phosphorus P and potassium K) and dose of fertilizer. The experiments show that potassium mineral fertilizer is the key factor for radionuclide accumulation control. The optimal dose of potassium is 90 kg per hectare. On the base of experimental results the model of cesium-137 accumulation in the wood for a 21 year has been developed. In accordance with calculation to the end of willow cultivation (21 year) concentration of cesium-137 in wood will not be higher than permitted even with the level of cesium-137 contamination in the soil 1480 kBq/m2 (maximum 140 kqB/m2 with permitted level for firewood is 740 Bq/kg.). The concentration of cesium-137 in the roots increases gradually and get maximum in 21 year (3000 kqB/m2). Our results confirm that in the sum about 0.8 million hectares of radionuclide polluted arable lands partly excluded from agricultural practice in Belarus could be used for willow biomass production.