Investigating organic fertilisers’ ability to mineralize during the first month of plant propagation

Abstract: There are many forms of organc fertilizers produced and sold in the EU, and it can be difficult to assess which ones are the best in regards of nutrient content and the rate of mineraliztion. Two separate trials were conducted to assess the mineralization rates of three different organic fertilizers, available for private customers, on the Swedish market. One cow manure mix, one algae-based product and a solid fraction of biogas digestate were the tested fertilizers. The trials revealed that there were many differences in nutrient content and plant availability of said nutrients in the fertilizers. Analyses of the fertilizers’ contents showed both several high values of some elements, as well as some completely depleted valuable elements. It was concluded that the cow manure fertilizer performed best of the treatments, in respect of mass of the model plant. The Algomin fertilizer and the biogas digestate fertilizer had more substrate nutrient content than the cow manure fertilizer, but it did not reflect in the size of the tomato plants grown in those treatments.