Liming of acid tropical soils: practice, prospects and constraints.
The incidence of high acidity of tropical soils has been a major constraint to the availability, use and use efficiency of both native and added plant nutrients with negative impacts on sustainable soil fertility management. Ameliorating this condition has led to the use of liming materials packaged as a component of chemical fertilizers. But the incidental inclusion of liming materials in fertilizers has not been effective and sustainable due to the intensive land use activities, constant application of acid-forming chemical fertilizers, leaching losses of bases and crop removal. Liming materials themselves vary in their calcium and magnesium contents and ultimately vary in their efficacy in neutralising acid soils. Also, some soils may have less lime requirements than others, thus, influencing decisions on amount of lime materials required under different conditions. This paper therefore reviews the existing practices of lime application to acid tropical soils with the objectives of assessing their effect on soil pH, nutrients availability, soil properties and plant nutrition as well as evaluating the potentials of a particular liming material, taking into consideration variations in soils of different agro-ecologies.
Keywords: Liming materials, tropical soils and soil acidity.