Liming

Liming is defined as the application of ground calcium and/or magnesium carbo­nates, hydroxides, and oxides. Liming the soil is the most common and oldest method for reducing soil acidity. Liming is often performed through high-dose applications of products such as calcitic lime (CaCl2) and dolomitic lime [CaMg (СОз)2]. The aim is to increase the soil pH and therefore to modify the physical, chemical, and biological parameters of the soil. Studies have shown that liming materials affect the activity and composition of microbial populations and can create better environmental conditions for the development of nonacidophilic microorganisms, resulting in increased microbial biomass and soil respiration (Neale et al. 1997; Tate 2000). Nevertheless, liming has some limits; the effec­tiveness of surface application of lime to soils under a particularly no-till system withregard to subsoil acidity is uncertain, agricultural liming materials are rela­tively insoluble, and lime effects may be restricted to the top few centimeters of the soil surface for many years (Shainberg et al. 1989; Costa and Rosolem 2007).

Large quantities are generally required to improve plant growth, and for many resource-poor farmers in the tropics carrying out semisubsistence agriculture, its use is effectively prevented by the unavailability or the high cost of lime, or both (Haynes and Mokolobate 2001).