Abstract
Calcareous soils, primarily characterized by the presence of calcium carbonate (CaCO₃) and associated carbonate minerals, play a fundamental role in regulating soil chemical equilibrium, pH regime, buffering capacity, nutrient availability, and structural stability. Through these interconnected mechanisms, calcareous conditions exert a direct influence on agricultural productivity as well as on broader environmental outcomes. Elevated soil pH values and the abundance of bicarbonate ions in calcareous systems promote the precipitation of phosphorus (P) and the reduced solubility or strong surface adsorption of essential micronutrients such as iron (Fe), zinc (Zn), and manganese (Mn). These processes frequently result in lime-induced chlorosis, yield reductions, and quality losses, particularly in fruit crops and nutritionally sensitive field crops. In contrast, acid soils, where carbonate content is absent or extremely limited, occupy a substantial proportion of the world’s arable land. Under such low-pH conditions, nutrient availability is constrained, aluminum and manganese toxicity may occur, and the solubility of potentially toxic elements increases, leading to distinct limitations on crop growth and root development. In these systems, liming represents a classical and indispensable soil amelioration practice, as it raises soil pH, increases base saturation, improves cation exchange processes, enhances soil aggregation and structural resilience, and stimulates microbial and biological activity. Beyond agricultural production, soil inorganic carbon (SIC) associated with carbonates constitutes one of the largest carbon pools in terrestrial ecosystems and plays a complex role in greenhouse gas dynamics and climate regulation. Whether SIC functions as a net atmospheric carbon dioxide (CO2) sink or source depends largely on the origin of calcium, fertilization intensity, and land management strategies. In acid soils, liming is commonly regarded as a practice that directly generates CO2; however, the accompanying increase in soil pH may simultaneously reduce nitrous oxide (N2O) emissions by altering nitrogen transformation pathways, while excessive liming can enhance ammonia (NH₃) volatilization. In this context, the use of biomass-derived ashes with low heavy-metal content and silicate-based materials such as feldspar and perlite offer promising integrated management options by improving nutrient availability while contributing to long-term CO2 sequestration. Consequently, sustainable agriculture in both calcareous and acid soils should move beyond short-term yield-oriented approaches and adopt integrated environmental soil management strategies that explicitly account for greenhouse gas emissions, carbon sink potential, and climate change mitigation.
| Keywords: | Lime (CaCO3) Calcareous Soils Nutrient Availability Soil Inorganic Carbon (SIC) Greenhouse Gas Emissions Climate Change |