A new study shows that exposing hydrochar made from pig manure and mandarin peels to simulated sunlight significantly improves its ability to restore degraded soil. The research, published in Carbon Research, found that solar aging creates micropores and releases bioavailable organic compounds that feed beneficial soil microbes like Geobacter and Bacillus. In paddy soil tests, soil organic carbon increased by 53% to 110% and total nitrogen rose by 14% to 28% over 45 days. This method uses sunlight instead of energy-intensive chemical treatments to activate the char, making it a low-cost tool for carbon storage and soil regeneration. The study highlights a practical path for circular agriculture by turning wet biomass waste into a soil amendment that boosts fertility and microbial activity without heavy industrial inputs. For carbon markets and climate-focused farming, this could offer a scalable way to sequester carbon while improving crop yields.
