Effects of percolating water with graduated acidity upon the leaching of nutrients and the changes in some chemical properties of mineral soils

Authors

• František Haman University of Helsinki, Department of Agricultural Chemistry

DOI: https://doi.org/10.23986/afsci.71941

Abstract

Leaching of nutrients and the changes in some chemical properties of surface soil layer treated with solutions of gradual acidity were followed under laboratory conditions. The 25-cm-high columns of three soils, (A – fine sand, B - loam, C - clay loam), placed in plastic tubes were treated with deionized water (pH 6) and with three solutions (pH 5, pH 4, pH 3) of sulphuric acid. The washed out were determined in the leachates collected into plastic bags. The largest amount of nitrogen found in the leachates was in the form of nitrate and this was proportional to the content of organic matter in the soils. The leached amount of NH4-N was considerably lower and like potassium it was negatively dependent upon the clay content in the soils. The concentrations of K, Ca and Mg in the leachates rose in relation to the declining pH of percolating solutions. Especially in soil A, acid solutions of pH 5 (and lower) washed out very effectively the cations. Soils Band C (with a higher content of clay particles) showed a higher resistance to K, Ca and Mg leaching. The acidified water influenced even the pH of the surface layer (0—7,5 cm) of soils in the columns. The most marked decrease in pH values was found in soil A after an application of the solution with pH 3. A decrease in the content of basic cations (Ca and Mg) was parallel to the acidification of the upper layer of the soils.