Exchangeable cations in Finnish soils

Authors

• Ulla Marttila University of Helsinki, Department of Agricultural Chemistry, Pihlajamäki

DOI: https://doi.org/10.23986/afsci.71634

Abstract

An attempt was made to study the cation exchange capacity, the percentage base saturation and the amounts of the most common cations in the different types and depths of the Finnish soils on the basis of a material of 100 soil samples from various parts of the country. The exchangeable cations were leached from the soil with neutral 1N ammonium acetate. Calcium, magnesium, potassium, sodium and hydrogen were determined and the exchange capacity was calculated as the sum of all these cations. In the different soil types the mean values of the CEC were the following: organic soils 92.1 me per 100 g of soil, non-Litorina clays 28.9 », Litorina clays 27.9 », loam and silt soils 16.9 », sand and fine sand soils 14.5 ». The highest values of the percentage base saturation, on an average 85 % were obtained in the Glacial clay soils and the lowest ones in the organic soils, 34%, and in the Litorina clay soils, 36 %. BS % was generally greater in the deeper than in the surface layers. The contents of clay (<2μ) and organic carbon explained 70 per cent of the variation in the exchange capacity of the mineral soils. Among the exchangeable cations the magnesium content seemed to be relatively high especially in the clay soils, except in the Litorina clays. The contents of potassium and sodium seemed to be relatively rather low in the organic soils. In the deeper layers exchangeable magnesium appeared to be higher than in the surface layers in all soil types. The amount of exchangeable sodium seemed also, on an average, slightly increase with the depth. Generally, the results agreed well with the previous studies carried out in Finland.