Marketable fertilizers may be formulated from chicken manure and pig slurry with the addition of biochar and vermiculite and be produced by the process of slurry seperation, therby reducing the volume and increasing the concentration of nutrients. The production of such fertilizers could ensure a better nutrient balance on lifestock farms where nutrient surpluses are frequent as a result of large amounts of slurry produced, with farms where nutrients are deficient. By testing fertilizers in a pot experiment, it was found that an organic fertilizer made from chicken manure and solid part of separated pig slurry (KP), works as effectively as a mineral NPK fertilizer. Growth and development of white cabbage (Brassica oleracea var. Capitata L.) and barley ječmena (Hordeum vulgare L.), as well as their yields in fertilization with NPK were equivalent to that in fertilization with prototype fertilizers made of chicken manure and pig slurry (KP). Other prototype fertilizers with the addition of vermiculite (KPV) and biochar (KPO) were not as effective, but the yields were stil higher than in unfertilized or in compost fertilized observations. The content of elements (N, P, K, Zn, Ni, Mg) in plants and soil samples did not differ significantly among individual treatments. The addition of biochar to the mixture of chicken manure and separated solid pig slurry (KPO) reduced the nitrate nitrogen content in the soil by 15 – 16 % compared to KP and NPK. In contrast, the addition of vermiculite (KPV) even slightly increased the content of available, potentially leachable nitrate-N in the soil compared to KP and NPK.
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