Biochar is the term for the solid residue that remains when biomass such as straw or wood chips is degassed by pyrolysis. The process takes place at high temperature without oxygen, and after the pyrolysis, the biochar still contains between 10-50% of the carbon of the original biomass. At a webinar in connection with the Plantekongres 2022, Lars Elsgaard, associate professor at the Department of Agroecology at Aarhus University, will explain how biochar can be used to improve the build up of carbon in the soil, and why biochar can be used as a climate tool.

Carbon storage and greenhouse gases

One of the benefits of adding biochar to the soil is that it increases the storage of carbon because biochar is very slowly degradable. This means that the emission of CO2 into the atmosphere will be less.

"Biochar is a way in which we can convert the CO2 that plants have absorbed from the atmosphere into a stable carbon form, which will only very slowly be re-emitted as CO2 into the atmosphere, perhaps over a period of many hundreds of years," says Lars Elsgaard, and continues: "In addition, biochar has a number of benefits for the soil's fertility, which is especially seen on depleted soil, but biochar can also help to reduce the emission of nitrous oxide, which is a very strong greenhouse gas".

But how does biochar actually work in the soil, and what effect does it have on the soil environment and the processes that form the greenhouse gases? Lars Elsgaard will talk about this at his webinar, which will be held on Thursday 13 January 2022 at 16.15 - 17.00.

Effects on the soil environment

In addition to having potential as a climate instrument, biochar has a number of other effects on the soil environment, both in terms of physical, chemical and biological properties.

It has been shown that some types of biochar can help to improve the soil's air exchange and transport processes. It can also help increase the soil's ability to retain water and nutrients in the root zone, which can potentially improve yields.

At the same time, biochar can affect the living conditions of the many microorganisms in the soil that help maintain important functions in the earth's ecosystem. The understanding of the interaction between biochar and the biology of the soil will be elucidated in the webinar by Associate Professor Dorette Müller-Stöver, University of Copenhagen.

Great interest in biochar

The diverse and generally positive effects of biochar on the soil's ecosystem and greenhouse gas balance have led to an increasing scientific and practical interest in the use of biochar on agricultural land. However, a number of challenges remain before large-scale use of biochar for agricultural land can become a future scenario for reducing greenhouse gas emissions from agriculture. Some of the challenges relate to longterm effects on the soil ecosystem, which are still poorly illuminated, just as it is important to emphasize that biochar is a collective term for products formed by pyrolysis of biomass. Depending on the type of biomass and the process conditions of the pyrolysis, the biochar formed can have different properties, which must be characterized for the individual product.

Hear much more at the webinar "Biochar's effect on agricultural land" on Thursday 13 January 2022 at 16.15 - 17.00. The two titles are: ‘Effect of biochar on soil biology’ and ‘Biochar’s effect on building up soil carbon and as a climate tool’.

Virtual Plant Congress

This webinar is part of the Plant Congress 2022. Again this year, the Plant Congress is being held virtually due to the Covid-19 pandemic. But the content is still the same, now you can just follow the many exciting presentations at home from the living room when they are held as webinars. In addition to this webinar, you can hear about:

• Changes in carbon content in Danish agricultural soil - The latest figures for Danish agricultural soil's carbon content are presented. 
• Reeching the target of zero emissions - Production of fertilizer and nitrous oxide emissions from the field are heavy items in the climate footprint of cereal crops. Hear about a new strategic effort to reduce greenhouse gas emissions from plant production and how you can reduce emissions in the field using new cultivation strategies.
• Diseases in cereal crops - Get the latest experimental results and strategies for controlling fungal diseases in cereals will be presented. Also hear how the new fungicide Balaya fared against Septoria in winter wheat in 2021, and get an idea of ​​the future use in winter wheat. In addition, there is a focus on fungal control in other cereal crops.

Read more about Plantekongres 2022 here www.plantekongres.dk (in Danish)