Fast-dissolving calcium carbonate particles as a high-performance lime for amelioration of agricultural acidic soils

Abstract

Effective soil management is essential for maximizing crop yields, as soil fertility plays a pivotal role in this process. Unfortunately, liming and fertilization practices are frequently ineffective, leading to overdoses and unnecessary product waste. Liming is essential for correcting soil acidity, mitigating aluminum toxicity, and promoting nutrient bioavailability before fertilizer application. This study explores the potential of vaterite, a highly soluble CaCO3 polymorph, as a sustainable liming agent. Vaterite particle synthesis is challenging because of its poor stability and rapid phase transformation into calcite, therefore, we analyze the effects of precursor concentration, Ca2+/CO32- ratio, and stirring rate on vaterite morphology and content in a reactive precipitation process through screening and D-optimal experimental designs, resulting in a design space to tailor the conditions that promote vaterite particles with a high dissolution profile at the lowest possible cost. To assess the efficacy of fast-dissolving CaCO3 particles, a comparative incubation test was conducted in andisol-type soil with a high buffering capacity. The results demonstrated that vaterite particles were capable of quickly adjusting the soil pH in the first few days using 360% fewer conventional liming agents. This innovative strategy aligns with Precision Agriculture principles, enabling efficient crop production while minimizing the environmental impact.