ENERGY EFFICIENCY OF SELECTED ORGANIC FARMS AND THEIR INFLUENCE ON GREENHOUSE GASES EMISSION

Summary

Energy efficiency and greenhouse gas (methane and nitrous oxide) emissions were investigated in 2003 on 20 organic farms in the central part of Poland (Kujawsko-pomorskie voivodeship) using a questionnaire developed in the Institute of Soil Science and Plant Cultivation in Pulawy (Poland). Statistical data from the Central Statistical Office concerning the agriculture in the Kujawsko-pomorskie voivodeship was also used. A simple index (Ee) defined as a ratio of the total energy value of agricultural production (Pe) to the material and energy inputs (Ne) (in MJ) was used to evaluate the energy efficiency. The average value of this index was 2.05; however, it ranged from 0.04 to 16.59. In the organic farms, direct energy carriers (liquid and solid fuels and electric energy) contributed most (about 45%) to total energy inputs. Plant products had the biggest share in total energy value of the yields (81.7%), of which cereals were the most important component (56.4%). Animal products had only an 18.3% share, dominated by meat. Average methane emission per ha of agricultural land (AL) was 36 kg per year, 8 kg more than the average value for the whole voivodeship. This was mainly due to the higher cattle density on organic farms. Emission of N2O from the organic farms was about half the average of others in the voivodeship. In the group of 20 organic farms, total methane and nitrous oxide emission expressed in units of Global Warming Potentials (GWP) was 985 and was 45 units less than the average for the Kujawsko-pomorskie voivodeship.