Soils as CO2 sinks? - The importance of dynamic disequilibria in soil systems

Climate and land-use change induce dynamic disequilibrium in C cycling (Luo & Weng TREE 2011) as does soil erosion (Doetterl et al. ESR 2016) and soil meliorations, e.g. deep tillage (Alcantara et al. GCB 2016, Schiedung et al. GCB 2019). The effect of disequilibria on decadal  trends of SOC in arable soils is demonstrated in controlled, long-term field experiments, which include desurfacing as well as meliorative fractional deep tillage (mFDT). Our results show that soil systems well below equilibrium state induce a fast, significant and sustainable CO2 sink effect. Especially mFDT offers a realistic, practical option for 4p1000 as it increases crop yields and soil fertility in arable soils simultaneously.