Assessment of Biomass and Biochar of Maritime Pine as a Porous Medium for Water Retention in Soils

The authors thank the staff of the Laboratório de Física do Solo (MED) for all their help in determining the water retention curves. The authors would like to thank to Bio Green Woods company for the support of providing biochar feedstock and allowing technological knowledge and opinion exchanges. Funding Information: The APC was funded by IDMEC, under LAETA. Publisher Copyright: © 2022 by the authors. ; Pinewood biomass in Portugal can be considered a major source of biochar for soil physical, chemical, and biological edaphic amendment. This work intended to evaluate the aptitude of lab produced biochar for upgrading soil moisture dynamics’ relationships considering mixtures of biochar with silica-based sand. The methodology used focused on the carbonization of pine biomass with inert atmosphere at 300 °C, 400 °C, 500 °C and 600 °C, followed by a chemical proximate and thermogravimetric analysis, scanning electron microscopy, Fourier Transform Infrared analysis, numerical modeling, and characterization of biochar porosity by gas adsorption (Brunauer–Emmett–Teller) and mercury porosimetry. The results showed the increased amounts of soil water retention and plant available water, evaluated through pF curves, due to biochar application. The thermogravimetric analysis mass loss patterns and FTIR transmittance, reflected major structural modifications in carbonized products by comparison with raw biomass. Mercury porosimetry showed that biochar pores between 392 and 250 μm and 32 μm and 6 μm gave the highest pore volume for water retention with a major increase from carbonization, by comparison with physical activation. The used methodologies allowed us to conclude that the carbonaceous feedstock can potentiate the improvement of soil water relations aiming at agricultural land use. ; publishersversion ; published