Han, et al (2024) Modeling biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More effects on soil organic carbon on croplands in a microbial decomposition model (MIMICS-BC_v1.0). Geoscience Model Development. https://doi.org/10.5194/gmd-17-4871-2024

The application of biochar to croplands is recognized for its potential to sequester carbon and improve soil quality. However, its impacts on soil organic carbon (SOC) dynamics are often not represented in current land models, which limits our understanding of biochar’s effectiveness under varying climate and land management conditions. To address this, researchers developed a biochar submodel integrated into the MIcrobial-MIneral Carbon Stabilization (MIMICS) model.

MIMICS was calibrated and validated using global data from 285 cropland sites. The model incorporated key processes such as density-dependent microbial turnover, organic carbon adsorption to mineral soil particles, and soil moisture effects on decomposition. By integrating biochar, the model now accounts for its influence on microbial decomposition and SOC sorption/desorption processes. Two biochar-related parameters were optimized using 134 paired SOC measurements.

The enhanced MIMICS model, termed MIMICS-BC, successfully reproduced both short-term (≤ 6 years) and long-term (8 years) SOC changes after biochar application with a high degree of accuracy (R² = 0.79 and 0.97, respectively). This model is a significant improvement, offering a useful tool for evaluating biochar’s role in removing CO₂ from the atmosphere when coupled with dynamic land models.

Biochar application affects SOC mineralization through various mechanisms, resulting in either positive or negative priming effects on SOC. The inclusion of sorption and soil moisture processes in MIMICS-BC extends its capacity to simulate these dynamics effectively. This study provides a critical advancement in soil carbon modeling, enabling better predictions of biochar’s impact on SOC and aiding in the development of climate change mitigation strategies.