Valorization of Pyrolysis Residues as Organic Amendments for Soil Fertility Improvement

Sustainable management of organic residues is a major challenge for modern agriculture. Pyrolysis appears as a promising technology to convert biomass into a stable carbon-rich material called biochar. The aim of this study was to evaluate the potential of pyrolysis residues from whole Malagasy zebu horns (Bos indicus) as an organic amendment to improve soil fertility. Pyrolysis, carried out at controlled temperatures (450–490 °C) in a handmade furnace, resulted in a mass yield of approximately 40 %. The residues showed a high ash content (66.19 %), low moisture (4.09 %), and notable concentrations of major nutrients: total nitrogen 3.59 g/100 g, phosphorus 3.34 g/100 g, and potassium 0.089 g/100 g. Incorporation of these residues into soil could enhance water retention, nutrient availability, and organic matter stability. This study highlights the agronomic and environmental value of valorizing pyrolysis residues within a circular economy approach.

Author Keywords: Pyrolysis, biochar, soil fertility, organic amendment, residue valorization, sustainable agriculture.