Koldioxidavgång vid ekologisk odling på organogen jord

Abstract: The background of this work is the media discussion about the effect of cultivation on peatsoils on greenhouse gas emissions. It has been argued that row sown and intensivelycultivated crops such as carrots are more likely to emit carbon dioxide than for example grassleys. The association KRAV (an association promoting organic farming) shall, from this yearadapt their environmental policy to be more climate smart and have asked the question if thecultivation of some crops is more climate smart than others? Carbon dioxide emissions fromsoil are due to degradation of organic material and the rate is controlled by microbial activity.The microbial activity is determined by a variety of factors such as temperature, soil organicmatter quality and water content. I have measured the carbon dioxide emission from fourdifferent crops at two different farms. At Åloppe which is an organic farm, I have comparedcarbon dioxide emission from grass leys and carrot grown on peat soil. At Ekhaga which isSLU's experimental farm for organic farming; I have compared spring wheat and potatoesgrown on gyttja soil. The results show no significant difference in carbon dioxide emissionswhen growing these crops on organic soils. The emission levels where the same on both soiltypes. The amount of water in the soil and the temperature affect the carbon dioxide emissionbut the results are very uncertain. Biological systems usually have a peak activity range whenall environmental factors are optimized, and so does this system. A moderate amount of waterand air in the soil and a high enough soil temperature resulted in the highest carbon emission.I also studied how the above-ground biomass reflects the underground biomass, knowledgethat can be used to get an idea of the crop root respiration. Because carbon dioxide emissionsdepend on many factors, you need to have a comprehensive view on cultivation practices.With an open mind you can go far in today's environmentally conscious society.