The Dependence of Reed Canary Grass (Phalaris arundinacea L.) Energy Efficiency and Profitability on Nitrogen Fertilization and Transportation Distance
Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences,
1 Kreutzwaldi Srt., EE51014 Tartu, Estonia; e-mail: email@example.com
The increased interest in bio-energy production forces us to consider production sustainability which in turn requires energy crop multi-criteria evaluations. The current study analyzes the dependence of reed canary grass (Phalaris arundinacea L.) energy use efficiency and production profitability on nitrogen fertilization and biomass transportation distance. The study used yield data from reed canary grass field experiments conducted in Estonia in 1968-1976. In reed canary grass production, nitrogen fertilization influences the biomass yield significantly and therefore has an impact on production energy efficiency. Although reed canary grass net energy yield increases continuously (0.15 GJ kg-1) with increasing nitrogen application, the optimum energy use efficiency is reached with 117 kg N ha-1. Increased reed canary grass transportation distance results in an average energy efficiency decrease of 7 MJ GJ-1 km-1. Reed canary grass cultivation for bio-energy
production could be considered at a break-even price of 1.5 EEK kg-1, whereas production profit-loss in this instance depends on nitrogen application. Supplementing profitability analysis with transportation costs results in production net cost and therefore also an increase in break-even price. In the current economic situation the actual buying-up prices do not exceed the production net costs, which is why the negative profitability in reed canary grass bio-energy production must be considered. As the current study evaluated reed canary grass production efficiency on soils with low soil humus content, there is a necessity of extending the study to soils with different fertilizer requirements. The methodology of the current study could be used for evaluating bio-energy production optimization in general despite the results being based on one field experiment.