Chen, et al (2024) Long- term successive 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 application increases plant lignin and microbial necromass accumulation but decreases their contributions to soil organic carbon in rice–wheat cropping system. GCB Bioenergy. https://doi.org/10.1111/gcbb.13137

A recent study published in GCB Bioenergy explores the long-term effects of biochar application on plant lignin and microbial necromass in a rice-wheat cropping system. Conducted over a decade, the study investigates how varying intensities of biochar application affect soil organic carbon (SOC) content and the contributions of plant-derived carbon (PDC) and microbial necromass carbon (MNC) to SOC.

The research found that biochar application significantly increased SOC content and stock, with higher application rates resulting in more substantial increases. Specifically, SOC content and stock rose by 32.6% to 203% and 26.4% to 145%, respectively, across different biochar treatments. Higher biochar application rates also enhanced soil pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More, total nitrogen (TN), total phosphorus (TP), and root biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More.

Moreover, the study observed that biochar application led to higher accumulations of plant lignin phenols and MNC. However, despite these increases, the relative contributions of lignin phenols and MNC to SOC decreased with higher biochar application rates. This reduction is attributed to the disproportionate increase in SOC compared to PDC and MNC, highlighting a dilution effect.

Interestingly, the research indicates that fungal necromass contributes more to SOC than bacterial necromass, though the fungal/bacterial necromass ratio decreased with higher biochar application rates. This shift is due to the greater abundance of bacteria stimulated by higher biochar levels.

The findings suggest that while biochar application boosts SOC by increasing plant lignin and microbial necromass, the direct contribution of biochar-derived carbon becomes a more dominant factor in SOC accumulation over time. This study underscores the complex interactions between biochar, soil properties, and microbial communities in enhancing soil carbon sequestration and fertility in agroecosystems.