Effect of Lime Source, Fineness and Granulation on Soil Permeation with Contrasting Textures under Simulated Mediterranean Climate Rainfall Conditions

Abstract

Granulated micro-fine limes have recently been introduced as liming materials which are purportedly more effective than conventional agricultural limes in terms of rapidly correcting subsoil acidity in no-tillage systems. Hydrated limes are known to react more quickly in soils than calcitic limes, yet their soil permeability has not been evaluated under Mediterranean climate growing conditions. Therefore, the aim of this controlled study was to compare soil permeation and pH neutralization of different liming materials (hydrated lime, calcitic agricultural lime, micro-fine lime and molasses-granulated micro-fine lime) in two contrasting (sand and sandy loam) acid (pH_KCl < 4.1) topsoils under simulated Mediterranean climate conditions. Limes were surface applied to 40 cm soil columns and then rainfall (350 mm) was simulated. Subsequently, soil chemical properties (pH, exchangeable cations, available P) were measured in 5 cm increments. Application of all liming materials increased soil pH 1–2 pH units above target pH_KCl of 5.5 in the top 5 cm of both soils. Only hydrated lime was able to increase soil pH_KCl (5.7–6.8) below 5 cm up to a depth of 15 cm on the sand soil. Hydrated lime, however, resulted in substantial over-liming (pH_KCl 7.3–8.7) of the top 5 cm of soil compared to the other materials. Granulated micro-fine lime reacted more slowly than the agricultural limes and is therefore not a suitable quick-fix for subsoil acidity in rain-fed no-till systems under Mediterranean climate rainfall conditions. Whereas hydrated lime showed potential in ameliorating subsoil acidity in the sand soil within one season of rainfall.