Sorption properties of granulometric fractions in Haplic Cambisol developed from boulder loam

Abstract

The aim of the paper was to investigate the sorption properties of granulometric fractions separated from the genetic horizons of arable Haplic Cambisol developed from boulder loams of the Middle-Polish (Riss) Glaciation, Wartanian Stadial (central Poland). Separation of granulometric fractions was made with application of the Atterberg method without the use of centrifuging and dispersing agents. The cation exchange capacity average value in cmol(+)kg−1 and % contribution in particular fractions reached: 1–0.1 mm – 2.1 (1.6%), 0.1–0.05 mm – 5.5 (4.0%), 0.05–0.02 mm – 8.5 (6.1%), 0.02–0.01 mm – 13.0 (10.1%), 0.01–0.005 mm – 16.1 (12.8%), 0.005–0.002 mm – 28.6 (20.5%) and fraction <0.002 mm – 48.7 (44.9%). Leaching of the total exchangeable bases was the largest in the 0.1–0.05 mm fraction and decreased successively with decreasing grain diameter. Sorption properties of the tested soil determine its high agricultural value and buffer properties. The cation exchange capacity of the recognised granulometric fractions successively increased with decrease of their diameter while leaching process intensity in individual fractions decreased gradually as their dimensions decreased. Calcium was the most leached cation, followed by magnesium and sodium, whereas potassium was not leached at all. Significant increase of the cation exchange capacity in fractions from carbonate horizons was mostly caused by the increased contribution of calcium, which could be released from carbonates during extraction of bases.

Keywords

• granulometric fractions
• cation exchange capacity
• leaching process