Leaching of nutrients from mixed fertilizer in some Finnish soils

Authors

• Johan Korkman University of Helsinki, Department of Agricultural Chemistry

DOI: https://doi.org/10.23986/afsci.71773

Abstract

The movement of fertilizer nutrients in soil was followed in ten soils under laboratory conditions. The 20 cm high soil columns in plastic tubes were top-dressed with a mixed fertilizer, 15—20—14, and irrigated twice with 30 mm of water each time. The distribution of the nutrients was determined from the leachate and the extracts of dilute sulphuric acid. Under these conditions, the average distance the nutrients moved downward was 17 cm for NH4—N, 10 cm for P and 14 cm for K. The weighted mean of the nitrate concentration distribution was located 11 cm beneath the surface. The distribution of the ammonium nitrogen and the potassium was correlated to the clay content of the soil (r=—0.74*, r=—0.80**). The percolation rate of the nitrate was correlated to the combined influence of organic carbon and clay, though the structure of the soil samples was destroyed before the experiment.