Long-term grass lawn management increases soil organic carbon sequestration and microbial carbon use efficiency

Abstract

Climate change mitigation is a global challenge that demands effective strategies to reduce atmospheric carbon concentrations. Grass lawns can sequester a significant amount of atmospheric carbon in soil contributing to mitigate climate change. However, it is not clear whether long-term management of grass lawns continues to sequester atmospheric carbon effectively. By using four different grass lawns established within five (GL1), fifteen (GL2), fifty (GL3), and eighty years old (GL4), this study assessed soil organic carbon (SOC) stock, carbon management index (CMI), cumulative SOC mineralization, and microbial metabolic quotient (qCO₂). Results showed that the grass lawn managed for 80 years (GL4) had the highest SOC stock (+ 67%) and sequestration (+ 140%) compared to the young grass lawn (GL1). Additionally, cumulative SOC mineralization rates were highest in GL4 (171%) compared to GL1. Notably, qCO₂ decreased in 80 years aged plot (-6%), indicating enhanced carbon use efficiency of microbial communities and highlighting the advantages of maintaining long-term grass lawns to support carbon sequestration. Furthermore, soil microbial biomass and carbon management indices are significantly enhanced but narrowed dissolved nutrient stoichiometry under aged grass lawn in comparison with newly established grass lawn. We conclude that long-term maintaining grass lawns offers an excellent strategy for carbon management to counteract the effect of changing climate and ecosystem restoration. This data set could serve as valuable resource for climate modeling and policy recommendations to improve soil organic carbon sequestration in low carbon soils.