Potassium–calcium and potassium–magnesium exchange equilibria in an acid savanna soil from northern Nigeria

Heterovalent cation exchange in two savanna soils of different lithogenic origin as described by the Rothmund–Kornfeld model

“…Generally, however, the information to be derived from the selectivity coefficients evaluated for the exchange reactions, regardless of the nature of parent material, is that the complex KX was more stable than MgX in the exchange reaction: 2KX +Mg 2+ =MgX 2 +2K + , and also more stable than CaX in the exchange reaction: 2KX +Ca 2+ =CaX 2 +2K + . Similar results were reported by Agbenin and Yakubu (2007) for an acid savanna soil of volcanic origin.…”

“…But cation exchange studies from savanna soils of Western Nigeria indicated a preferential K + to Ca 2+ and Mg 2+ retention by the soils (Udo, 1978;Pleysier et al, 1979). A recent study by Agbenin and Yakubu (2007) also established a preferential K + adsorption to Ca 2+ and Mg 2+ in a savanna soil whose formation had been strongly influenced by volcanic activities.…”

“…The experimental procedure for the ion exchange experiment had been described in details elsewhere by Agbenin and Yakubu (2007). Briefly, 5 g of b2.0 mm sieved surface and subsurface samples were weighed into pre-weighed centrifuge tubes.…”

Effect of sodium and magnesium on kinetics of potassium release in some calcareous soils of western Iran

“…Hunsaker and Pratt (1971) found that montmorillonite soils showed a preference for Ca over Mg, while Rahman and Rowell (1979) reported that illite and vermiculite showed a preference for Mg over Ca. Agbenin and Yakubu (2006) studied potassium-calcium and potassium-magnesium exchange equilibria in an acid savanna soil from northern Nigeria. They found that in variable charge soil dominated by kaolinites K is selectively retained by the soils as compared to Ca and Mg.…”

Comparing Extraction and Quantity/Intensity Based Recommendations for Nitrogen, Phosphorus and Potassium Recommendation

“…Interactions between the ions also play a crucial role, and this relationship is commonly antagonistic in nature, hence quantifying these ions by accounting for these interactions is mechanistically justified. Soil surface prefer divalent cations over monovalent cations, however this preference is not fixed, it is dynamic depending on the ratio of K:Ca:Mg, or even Na in sodic soils and Al in acidic soils (Agbenin & Yakubu, 2006;Chintala et al, 2013). The solution concentration is inversely correlated with the preference for a respective ion, so that when soils show higher preference for that particular ion its buffering capacity will be higher, and ultimately the effectiveness of fertilizer in increasing its concentration in solution will be lower.…”