Potential of Carbon Sequestration in Biominerals of Buglossoides arvensis (L.) I.M. Johnst. Fruits Under Contrasting Soil Calcium Content

Biomineralization in plant tissues is a widespread process accompanied by carbon sequestration in biogenic minerals. This study aimed to evaluate the effect of CaCO₃ application to soil on the yield of Buglossoides arvensis (L.) I.M. Johnst., on the formation and localization of biominerals in the pericarp of fruits, as well as on the accumulation of carbon in minerals. B. arvensis seeds were sown in clay loam soil treated with CaCO₃ at concentrations of 0.0 (0Ca), 2.5 (2.5Ca), 5.0 (5Ca), 7.5 (7.5Ca), and 10.0 (10Ca) t ha⁻¹. CaCO₃ application improved B. arvensis germination, plant biomass accumulation, fruit weight and number, which consequently increased both per plant and per area yield, but did not significantly affect the rate of photosynthesis and leaf respiration. Scanning electron microscopy analysis showed no significant effect of soil liming on the localization of amorphous silica and calcium carbonate in the pericarp of B. arvensis fruits. However, with increasing soil calcium availability, the silica to carbonate ratio changed towards a decrease in silica content and an increase in carbonate content. Liming of soil from acidic to slightly alkaline increased the content of organic carbon, occluded in biosilica (phytoliths) and also increased carbon content of calcium carbonate in the pericarp of B. arvensis fruits. We concluded that B. arvensis responds to increased soil calcium and soil pH by increasing carbon sequestration in biominerals formed in fruit pericarps. Studying the relationship between biomineralization in plants and environmental conditions may be useful for assessing key biogeochemical processes of carbon sequestration.