Study on the Impact of Compost and Cover Crops on Soil Carbon Sequestration
Tautges & Chiartas et al. (2019) have published a study looking at the impact of compost and cover crops on soil carbon sequestration. The study was funded by the US Department for Agriculture and can be read here.
Increasing soil organic carbon via organic inputs is a key strategy for increasing long‐term soil C storage and improving the climate change mitigation and adaptation potential of agricultural systems. A long‐term trial in California’s Mediterranean climate revealed impacts of management on soil organic carbon using different cropping systems: conventional; conventional with cover crops; and application of composts alongside cover crops. Soil organic carbon was measured at the initiation of the experiment and at year 19, at five depth increments down to 2 m, taking into account changes in bulk density.
Researchers found that the system that used both cover crops and compost, had significantly increased soil carbon content over the length of the study – about 0.7 percent annually.
The study suggests that compost plays a larger role than once thought in building soil carbon and that carbon levels fluctuate more in deeper soil.