The aim of the paper is to evaluate biomass production of three different willow varieties (Salix spp.) at the end of the first year of the second harvest cycle (2012) and to compare the results with those obtained in the first harvest cycle at the end of the first growing season after cutback (2008). The observed growth parameters included number of shoots per plant, shoot height and diameter, and weight of fresh matter per plant. Three willow varieties were studied (Tora, Gudrun and Tordis). The individual growth parameters were determined by destructive method. The number of the shoots per plant varied from 17.83 (Tora) to 30.17 (Gudrun). The shoot height ranged from 2.66 m (Gudrun) to 3.62 m (Tordis) and the shoot diameter ranged from 10.85 mm (Gudrun) to 13.14 mm (Tordis). The variety with the greatest biomass production of the fresh above-ground matter was Tora (5.43 kg plant-1), followed by Gudrun (4.97 kg plant-1). Tordis provided the lowest yield (4.55 kg plant-1). All of the observed growth parameters had higher values than those determined at the end of the first year after cutback in the first harvest cycle. The most significant increase was recorded in the above-ground biomass production with the percentage increase of 114%, 122% and 226% in Tora, Tordis and Gudrun, respectively.
The renewable energy sources play an important role in the discussions on the future energy generation. The European Union has set certain goals to increase the share of renewable energy sources and to reduce carbon emissions. The paper focuses on the evaluation of energy production from short rotation coppice (SRC) plantations in the cadastral area of Nové Zámky. The study area is located in south-western Slovakia. The energy production was evaluated based on GIS analysis of agricultural land suitable for establishment of short rotation coppice plantations. The high-quality arable land was excluded from the biomass production. The wood biomass should be produced on marginal, low-quality soils and contaminated or degraded land that is unsuitable for food production. There are only high and medium-quality soils classified in the qualitative groups 1–7 in the study area. The land potentially used for biomass production represents an area of 1,536 ha. If the whole area would be covered by short rotation coppice plantations, it would produce 4.8 kWh/day per person. Taking into consideration the overall losses of 33% in the process of the energy conversion, the potential power from the wood biomass production is 3.2 kWh/day per person. The plantations would provide 61 new jobs in the study area.
Zuzana Jureková, Marián Kotrla, Martin Prčík, Martin Hauptvogl and Žaneta Pauková
The energy-efficient low-carbon EU economy (known as the 20-20-20) sets fundamental objectives in reducing greenhouse gas emissions (20%), increasing the share of renewable energy sources (20%) and saving primary energy consumption (20%). The objectives are incorporated in the National Renewable Energy Action Plans (NREAPs). Slovakia has to increase the share of renewable energy sources (RES) by 14% in its energy mix by 2020. Currently, the most widely used RES are water and solar energy, biomass and biogas. Our country has suitable ecological conditions for growing the so called energy crops in lowland and upland areas. So far, however, there is a lack of science-based information on the potential production of biomass in different soil-ecological and climatic conditions of the Slovak Republic. Our experimental research is focused on quantification of biomass production of various willow (genus Salix), poplar (genus Populus) and silvergrass (Miscanthus sinensis) varieties grown in ecological conditions of southern Slovakia. We evaluated the biomass production of the studied crops. The results were evaluated in terms of the EU call (2013): to obtain more energy while reducing inputs and negative environmental impacts.
Zuzana Jureková, Dušan Húska, Marián Kotrla, Martin Prčík and Martin Hauptvogl
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.