Mitigating Soil Acidity: Impact of Aglime (CaCO3) Particle Size and Application Rate on Exchangeable Aluminium and Base Cations Dynamics

Abstract

Liming is an essential practice for neutralizing soil acidity, influenced by factors like lime particle size and application rate, addressing challenges from climate change, acid rain, nitrate leaching, and mineral oxidation. This study evaluated the efficiency of fine (0.1 mm) and coarse lime (1–2 mm) applied at rates of 3 t/ha and 6 t/ha in mitigating soil acidity, with a particular focus on their impact on subsoil characteristics. Over two years, key soil parameters were monitored, including pH, cation exchange capacity (CEC), and exchangeable base cations (Ca2+, Mg2+, K+), along with exchangeable aluminum (Al3+). Fine lime particles demonstrated superior effectiveness compared to coarser ones, leading to faster and more uniform pH increases due to their greater surface area and higher solubility. Lime application significantly improved CEC by reducing exchangeable aluminum and increasing calcium availability, particularly in the topsoil. While these effects were most pronounced in surface layers, aluminum toxicity remained a concern in deeper soil levels. Strong positive correlations were observed between lime application and soil parameters such as pH, CEC, and exchangeable cations, while aluminum showed a negative correlation. Principal component analysis confirmed the benefits of higher lime doses, with fine lime producing rapid improvements and coarse lime offering a slower but sustained effect on soil health.