Raissa Razeraa, Bruna Emanuele Schiebelbeina, Victória Santos Souzaa, Luis Fernando Vieira da Silvaa, Maurício Roberto Cherubina, b, David A.C. Manningc, Antonio Carlos de Azevedoa, b
- aDepartment of Soil Science, Luiz de Queiroz College of Agriculture (ESALQ), University of São Paulo (USP), Piracicaba, SP, Brazil
- bCenter for Carbon Research in Tropical Agriculture (CCARBON), University of São Paulo, Piracicaba, SP, Brazil
- cSchool of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
Highlights
- Mining by-products improved soil health in degraded tropical sandy soils.
- Combined claying and remineralization increased soil health index by 22%.
- Mineral amendments increased soil organic carbon stocks by 17% in 18 months.
- Rock dust transforms mining by-products into regenerative soil inputs.
- Brazilian experience shows circular economy pathways for agriculture.
Abstract
Mining by-products are an underutilized resource with strong potential for soil restoration within a circular economy. However, the combined effects of claying and remineralization on soil health remain unclear. We evaluated sedimentary rock powder (applied for claying at low [LC] and high [HC] rates), mafic rock dust (remineralization, R), and their combination (C + R) in a degraded tropical sandy pasture soil. After 18 months, soil (0–20 cm) was analyzed using the Soil Management Assessment Framework, integrating chemical, physical, and biological indicators into a soil health index (SHI). The LC + R treatment showed the best performance, increasing SHI by 22% and soil organic carbon by 17% compared to the control. Improvements were driven by chemical and biological indicators, while physical attributes showed limited change. Principal component analysis (PCA) confirmed treatment differentiation. Results demonstrate rapid soil response to mineral amendments, highlighting their potential as regenerative inputs for climate-resilient agriculture and circular economy strategies.
Keywords
Rock powder; Agromineral silicate; Remineralizer; Soil quality
