Somewhere in a coastal Chinese province, a pile of shells that would otherwise rot in a landfill just helped repair a stretch of tired, sour farmland. In a five-year field trial published in Frontiers in Plant Science in February 2025, researchers ground up leftover oyster shells and mixed the powder into acidic red soil on peanut farms in Jiangxi Province, China. The study found peanut yields increased up to 37% compared to untreated plots, and the soil itself became measurably healthier.
Why farmland keeps getting sour
