engleski

Cation exchange capacity of some acid soils in Eastern Croatia

The cation exchange capacity (CEC) or sum of exchangeable cations are an essential measurement in agronomy and soil science to estimate the physicochemical state of a soil, which may be a good indicator of soil quality and productivity. Soil testing laboratories do not usually provide a direct measure of CEC. Instead, often the CEC is calculated based on the quantities of base cations (Ca2+, Mg2+, K+ and Na+) extracted in the standard soil test (e.g. ammonium acetate). The study was conducted on 30 locations and 2 soil types (Luvisol and Stagnic Gleysols) in Eastern Croatia including only topsoil horizon (depth 0-30 cm). The soil samples (30) were analyzed for the following parameters: pH, organic matter, clay content, base cations (Ca2+, Mg2+, K+ and Na+), hydrolytic acidity, CEC and base saturation. Descriptive statistics showed that pH varied from 3.71 to 5.16 (average 4.22) on luvisol and 3.81 to 5.41 (average 4.40) on stagnic gleysols. Organic matter varied from 1.31 % to 2.86 % (average 1.97 %) on luvisol and 1.62 % to 3.11 % (average 2.26 %) on stagnic gleysols, while clay content varied from 11.95 % to 25.03 % (average 19.22 %) on luvisol and 10.76 % to 24.02 % (average 16.52 %) on stagnic gleysols. The highest value of CEC was recorded on stagnic gleysols (11.84 cmol(+)/kg) and values ranged from 7.01 to 17.52 cmol(+)/kg, while average value of luvisol was 11.60 cmol(+)/kg with range from 7.38 to 17.02 cmol(+)/kg. The highest value of exchangeable Ca2+ was recorded on stagnic glaysols (2832.0 mg/kg), while highest values of exchangeable Mg2+(460.7 mg/kg), K+ (452.7 mg/kg), and Na+ (27.80 mg/kg), was recorded on luvisol. The lowest value of exchangeable Ca2+ (291.80 mg/kg) and Mg2+ (55.47 mg/kg) was recorded on luvisol, while lowest value of exchangeable K+ (73.65 mg/kg) and Na+ (11.69 mg/kg) was recorded on stagnic gleysols. The average determined adsorption complex saturation luvisol amounted to 56.96 %, while the stagnic gleysols is 73.48 %. No significant difference was found between pH, organic matter, base cations (Ca2+, Mg2+, K+ and Na+) and CEC. Soil type was found to have significant influence on clay percentage, hydrolytic acidity and base saturation. It was obtained that stagnic gleysols has a significantly higher content of clay particles and hydrolytic acidity compared to luvisol, however it had significantly lower cation exchange capacity base saturation. According to the obtained results we can state that investigated soil belong to acid soils, with moderate organic matter content and moderate texture, average values of CEC are low (11.60 cmol(+)/kg on luvisol to 11.84 cmol(+)/kg on stagnic gleysols) and it’s not dependent on soil type, determined adsorption complex saturation of luvisol is statistically lower compared to stagnic gleysols and composition of cations on the adsorption complex is Ca> Mg> K> Na.

cation excange capacity ; acid soils ; luvisol ; stagnic glaysols

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