The aim of the experiment, conducted from 1973 to 1999, was to determine the effect of long-term fertilization with liquid manure (annual and biennial) and with mineral fertilizers on selected physicochemical and chemical properties of soil, i.e., the content of phosphorus, potassium, magnesium, sulphate sulphur, iron, manganese, pHKCl and organic carbon. Fertilization with liquid manure was observed to have resulted in a significant reduction in the content of soil-available phosphorus in comparison to fertilization with NPK. Fertilization with both liquid manure and NPK led to a significant increase in the content of available potassium and magnesium in the soil profile. The highest amounts of S-SO4 were reported from the topsoil layer, irrespective of the type of fertilizer applied. Fertilization with liquid manure and NPK caused an irregular rise in the content of iron soluble in 1 M HCl in the soil, whereas the content of manganese increased slightly and irregularly in response to the fertilization applied. A negligible rise in pHKCl of the topsoil layer was observed at annual application of increasing doses of liquid manure. It was reported that fertilization with liquid manure led to a steady rise in the organic carbon content in the soil profile.

17.2.2012