Soil Organic Matter and Its Role in Soil Health

Soil organic matter (SOM) is vital for healthy soil, supporting primary productivity, water regulation, carbon sequestration, biodiversity, and nutrient cycling. Comprising ~58% carbon, SOM is largely derived from atmospheric CO₂ via plant photosynthesis. In arable and vegetable soils, SOM levels range from 1% to 6% of total mass. Despite its low proportion, SOM profoundly influences soil’s physical, chemical, and biological properties—enhancing aggregate stability, water retention, nutrient availability, and microbial activity. It boosts soil resilience to drought, compaction, and extreme conditions. Conservation practices like reduced tillage, erosion control, and residue return are essential to maintain SOM. The BEST4SOIL project, funded by the EU’s Horizon 2020 Programme (grant 817696), highlights these benefits through comparative studies, such as aggregate stability in sandy loam soils with 7% vs. 2% SOM.