Showing papers by "Keith C. Cameron published in 1988"

Effect of cation exchange on the distribution and movement of cations in soils with variable charge. II. Effect of lime or phosphate on potassium and magnesium leaching

Abstract: The effect of Ca(OH)2 or Ca(H2PO4)2 ⋅ 2H2O (MCP) on potassium (K) or magnesium (Mg) leaching through and out of columns of soil with predominantly variable charge was studied. Calcium hydroxide was mixed with soil from the A and B horizon to raise the pH to about 6 or 7, and MCP, equivalent to 952 mg P, was mixed with the A horizon of each soil. Various concentrations of KCl or MgCl2 were applied as a pulse to the soil surface and leached with five pore volumes of deionised water.

Effect of cation exchange on the distribution and movement of cations in soils with variable charge. I. Effect of lime on potassium and magnesium exchange equilibria

Abstract: The influence of Ca(OH)2 on K and Mg exchange equilibria in three New Zealand soils was studied. Calcium hydroxide was mixed with each soil to raise the pH to about 6 or 7. For each Ca(OH)2 treatment, K and Mg exchange isotherms were determined, from which the equilibrium activity ratios were derived. Exchange coefficients and solution activity ratios were calculated according to the Gapon convention.