The combination of crushed rock and organic matter enhances the capture of inorganic carbon in tropical soils
F. P. Medeiros, S. H. Theodoro, A. M. X. Carvalho, V. S. Oliveira, L. C. Oliveira
ABSTRACT:
The use of remineralizers (REM) derived from crushed rocks has become an important option to ensure soil fertility and food and nutritional security, as well as a potential mechanism to capture CO2 efficiently, helping to mitigate climate change. The objective of this article is to present the direct and indirect effects of the use of REM in carbon capture processes through accelerated rock weathering. The tests were carried out in leaching columns where a type of rock (R), characterized as kamafugite, was used at a dosage equivalent to 40 t ha-1 incorporated into the soil (S), with or without the addition of organic compost (OC), with a dosage of 80 t ha-1, totaling four treatments with four replications: S, S + R, S + OC and S + R + OC. During a period of four months, controlled amounts of deionized water percolated the columns composed of soil, OC and R in the different treatments. The resulting leachate was collected and analyzed for 14 physicochemical parameters. After testing, the soil was sampled to evaluate fertility parameters. Significant differences (P < 0.05) were observed in the parameters Ca, Mg, K, S, Electrical Conductivity and pH in the leachates in the rock treatments compared to their respective controls, with emphasis on the effect of the rock in the presence of organic compost. In addition, increases of Mg, K, P and Mn were observed in the soil that received the rock compared to the unfertilized soil. Regarding the possibility of capturing inorganic carbon, we found statistically significant differences (P < 0.05) in the S + R + OC treatment compared to the S + OC treatment. These results confirm the potential of REM associated with organic compost (OC) to increase soil fertility and carbon capture, although in a smaller magnitude than what has been expected.
https://www.sciencedirect.com/science/article/pii/S0895981124004760
