| Problems of inconsistent initial pH in peat moss substrates created using standard formulas for agricultural limestone additions, and subsequent pH drift from the initial target may result from variations in the neutralization capacity of limestone and neutralization requirement of peat moss. This research was conducted to evaluate physical/chemical properties of limestone that may influence neutralization capacity and properties of peat moss that may influence neutralization requirement. Limestones from twenty North American quarries were wet-sieved into eight particle diameter fractions. Specific surface was measured for each fraction. Reaction times were determined on three size fractions. Particle size distribution, CaCO3 and MgCO3 content, internal porosity, hardness, soundness, specific gravity, and specific surface were analyzed in multiple regressions with particle size included and also held constant at three size fractions to determine effects on limestone neutralization capacity. Peat moss samples were selected from three Alberta, Canada mires to represent the maximum range of species composition within a range of decomposition. Cation exchange capacity, base saturation, inherent pH, buffer capacity and neutralization requirement were measured. These properties were analyzed in a multiple regression along with species composition, decomposition, and detritus to determine effects on peat moss neutralization requirement. Limestones differed significantly in specific surface for each particle diameter fraction and reaction times. There were significant variations in cation exchange capacity, base saturation, inherent pH, buffer capacity and neutralization requirement. Neutralization requirement was significantly correlated to base saturation, inherent pH, decomposition, S. angustifolium, sedge, [Ca 2+], [Mg2+], and [Fe2+]. Inherent pH increased with base saturation. Peat moss samples containing large amounts of S. fuscum had high cation exchange capacity and base saturation, and low decomposition. Adding specific surface to particle size and CaCO 3 will further characterize limestone neutralization capacity; however, the problems of inconsistent initial pH and pH drift will be better managed by ensuring an adequate amount of S. fuscum in the substrate. |
