5. Make biochar and use it in agriculture

Biochar is a charcoal-like substance that is sometimes used by gardeners, who add it to their soil to increase water and nutrient retention, improve soil structure and enhance plant health.

It can similarly be spread on farmland, where it might improve crop yields and reduce the amount of fertiliser that is washed out of the soil.

Biochar is created by heating plant matter (biomass) to high temperatures without oxygen present – a process known as pyrolysis. It can hold onto the carbon that was in the plant matter for many years – hence it acts as a carbon store.

Its ability to store carbon for long periods of time depends on what it is made from, how it is produced, and where the biomass is put.

It can be created from almost any kind of biomass, including domestic green waste and waste from agriculture and forestry. So it could provide a useful way of dealing with some types of waste.

However, some other types of waste, such as waste construction wood, may contain contaminants which could be introduced into the soil, so should be considered more carefully.

The Biochar Demonstrator is investigating how much and how long different types of biochar are able to store carbon for, what benefits or risks the biochar brings to farmers and the environment, and how people and communities perceive the use of biochar.