Farming systems and environmental impacts
Estonian University of Life Sciences, Kreutzwaldi 1A; e-mail: maarika.alaru@emu.ee
Abstract:
Energy crop production in organic farming. A basic principle of organic farming is to „reduce the use of non-renewable resources (e.g. fossil fuels) to a minimum”. Biomass is a key resource for biogas or biofuel. The main objective of this study was to find out the species and the species mixtures which could produce a high amount of above ground biomass for energy production. In 2007/2008 productivity of different field crops and grasses was investigated in natural, mineral fertilizer, slurry and wastewater sludge treatments. For field crops and grasses the productivity was studied in the case of pure and mixture sowings. The biomass chemical composition including heavy metals was studied. The highest above ground biomass was obtained from experimental treatments with maize cultivars, followed by hemp cultivars fertilized with wastewater sludge. The highest yield from grasses was obtained from smooth brome grass on mineral fertilizer background which was followed by reed canary grass on sewage sludge background. The lowest yield was obtained from cocksfoot. To avoid the damage of soil texture the wastewater as renewable nitrogen (N) resource should be used only after 3 years.