Contribution of organic waste products to soil carbon sequestration

Summary

At COP 21, France launched the international 4 by 1000 initiative, suggesting that an increase in soil carbon stocks of 4 per thousand per year could offset anthropogenic CO2 emissions, thereby contributing to carbon neutrality, a goal that the IPCC considers necessary by 2050. Carbon is the main component of soil organic matter. It plays a major role in maintaining and improving soil fertility and quality, as well as in providing numerous ecosystem services, including mitigating and adapting to climate change.

A great deal of research has been carried out on these subjects in recent years, particularly on the contribution of C to soils via organic waste products (OWPs). In fact, around 150 Mt of organic waste, which can be spread in agriculture, is produced every year in France. These products can play a role not only in sequestering carbon in soils, but also in improving degraded soils and fertilising them with nitrogen and phosphorus.

In order to increase awareness of the current state of knowledge, the RECORD association has produced this report, which provides a summary of what is known about carbon storage in agricultural soils, and illustrates this with an analysis of the agronomic, environmental and economic impact of spreading organic fertilisers in 4 defined areas. Finally, it delivers 9 key messages for stakeholders (farmers, local authorities, administrations), whether they are producers, users or prescribers.