Biochar as amendant

Biochar is a solid carbonaceous residue (with a carbon content greater than 60%) obtained from the pyrolysis and/or gasification of biomass, which is incorporated into the soil to improve its functionality.

It provides stable and very slow-release carbon to the soil, helps retain nutrients, is able to regulate and improve the water retention in the soil and is able to corrects its pH to alkaline values. Biochar can be used in contaminated soils, because with its chemical-physical properties, contributes to the fixation of heavy metals and improve the processes of biodegradation of organic compounds.

For this reason, the application of biochar as a soil improver plays an important role in the recovery of degraded soils; it can be applied to increase the fertility and water retention of agricultural land but also for the treatment of contaminated land.

When used in the case of application on less fertile soil, recent studies have shown how the combined application of biochar and organic amendments can lead to a further improvement in the physical, chemical and biological properties of the soil. In fact, the combined use of biochar and compost has a positive synergistic effect on the nutrient content and water retention capacity of the soil. Additional benefits of adding compost and biochar to soil include promoting microbiological activity, reducing losses due to erosion, improving structural stability, and increasing carbon sequestration capacity due to long-term stability of biochar. In the Mediterranean area, this integrated approach could contribute to the objectives of sustainable and ecological development, and to the mitigation of climate change. In Italy biochar is permitted by Legislative Decree 75/2010 on soil improvers/fertilizers (with 2015 update). It can therefore be used in conventional and integrated agriculture. With the EU Regulation 2019:2019, the way has been opened to marketing in combination with other soil improvers or substrates, to voluntary certification and to its use in organic farming.