Comparison Of Energy Sources Grown On Agricultural Land

The aim of the paper is to compare biomass production of energy plants and selected crops grown on arable land in the south-western Slovakia in 2007–2014, its energy value and the influence of decisive climatic factors on the size of the production. The data on yields of dominant crops grown in the agricultural farm were obtained from the statistical data of the farm. Aboveground biomass of willows and poplars was harvested at the end of the harvest cycle. Aboveground biomass of Miscanthus sinensis was harvested in 2010–2014, always in early spring period of the following year. Winter wheat, spring barley and maize grown for silage during the period 2007–2014 provided the lowest yields in 2010 and the highest in 2011 and 2014. The highest energy value was obtained from maize in 2014 (400.66 GJ ha⁻¹). The short rotation coppice poplars of Italian provenance yielded biomass with energy value of 951.68 GJ ha⁻¹ year⁻¹ at the end of the first three-year harvest cycle in 2012. The analysis of variance confirmed that there are highly significant statistical differences in the poplar biomass yield among the varieties and individual experimental years. The fast growing willows of Swedish provenance provided aboveground biomass energy value of 868.88 GJ ha⁻¹ year⁻¹ at the end of the first four-year harvest cycle in 2011. The biomass production of the perennial grass Miscanthus sinensis, depending on the growing period, can be expressed by a polynomial trend function. The highest biomass production was obtained in the third growing period (2012). At the end of the fifth growing period (2014), the yield amounted to 28.60 t ha⁻¹ of the dry aboveground biomass. The energy value of the aboveground biomass of Miscanthus reached 486.20 GJ ha⁻¹ in 2014. Differences in the biomass yield of the Miscanthus genotypes are statistically highly significant in each of the monitored growing periods. The growth and production process of the selected energy species reflect the specificities of soil and climatic conditions of the individual growing periods, as well as the ability of individual species and varieties to provide biomass production in the given conditions. Regression analysis of the produced aboveground biomass of the crops grown in the Kolíňany cadastre has not confirmed a statistical dependence in selected climatic parameterss.