Clay-organic complexes in a Polish loess soil

• Published in: International Agrophysics Vol. 31; no. 3; pp. 447 - 452
• Main Authors: Czyż, Ewa A., Rejman, Jerzy, Dexter, Anthony R., Jadczyszyn, Jan, Rafalska-Przysucha, Anna, Stanek-Tarkowska, Jadwiga
• Format: Journal Article
• Language: English
• Published: Lublin De Gruyter Open 01-07-2017; Polish Academy of Sciences, Institute of Agrophysics
• Subjects: Algorithms; Carbon; Carbon sequestration; Catchments; Clay; clay dispersion; Clay soils; complexed organic matter; Correlation analysis; Dispersion; Loess; Mathematical analysis; non-complexed clay; Organic carbon; Organic matter; Organic soils; Saturation; Soil organic matter; Soil quality; strip tillage; Tillage
• ISSN: 2300-8725; 0236-8722; 2300-8725
• DOI: 10.1515/intag-2016-0054

Complexes formed between clay and soil organic matter are important for carbon sequestration and for soil physical quality. Here, we use samples of loessial soil from South-East Poland to explore the phenomenon of complexing in loess. Soil samples were collected from a single catchment 8 years after the introduction of strip tillage and their compositions were characterized by traditional methods. Complexing was characterized in terms of the content of non-complexed clay which was estimated in two ways: firstly, by measurement of the content of readily-dispersible clay (which was assumed to be the non-complexed clay); and secondly, by calculation using algorithms that had been developed and evaluated previously. The calculations were based on the concept that, at carbon saturation, the clay/organic carbon mass ratio is equal to
. The calculations were done with a range of values of
. It was assumed that the correct value of
was that which gave the greatest coefficient of correlation between the measured values of clay dispersion and the predicted values of non-complexed clay. For the loess used, the optimum value was
= 14.