Soil acidification and lime quality: sources of soil acidity, its effects on plant nutrients, efficiency of lime and liming requirements

Abstract

Agriculture sectors support economy of most developing countries. InSub-Sahara Africa, the agriculture is predominantly based on rain-fedagricultural production of small, semi-subsistence, and increasingly fragmentedfarms. Thus, the farming is intensive and fields are concentrated on valleys,steep hillsides and mountains. This results in soil acidity, low fertility,accelerated soil erosion and low crop yields. Soil acidity affects crops inmany ways and its effects are mostly indirect, through its influence onchemical factors such as aluminium (Al) and manganese (Mn) toxicity, calcium(Ca), phosphorus (P) and magnesium (Mg) deficiencies and biological processes.The application of lime believed to enhance soil health status throughimproving soil pH, base saturation, Ca and Mg. It reduces Al and Mn toxicityand increases both P uptake in high P fixing soil and plant rooting system.However, the liming effects depend on its source, its characteristics,composition, purity and how finely it is ground. The estimation of limerequirement is constraining its use for smallholder farmers and young soilscientists. This study therefore aimed at highlighting the most causes of soilacidification, lime quality and lime requirement. This review article willserve as a guide for farmers and young soil scientists in addressing soil acidity and properly determining lime requirement.