2018/09/30: Agriculture has historically been a circular industry where crops use nutrients in the soil to grow which are then replaced through compost or manure. But globalisation and industrialisation of the food supply chain has disrupted this cycle, driving farming practices that have helped degrade a third of the planet’s land.
Scientists are now looking at ways of tackling this problem with an approach that will not only restore nutrients to the soil but also help to offset the greenhouse gas emissions produced by agriculture.
‘Farm land could work as carbon sinks,’ said Dr Jan Mumme, an agricultural engineer at the University of Edinburgh in the UK. ‘This probably wouldn’t work with intensive livestock farming, but sustainable crop production and integrated farm systems (a balance between crops and livestock) could do it – and biochar is one way to help.’
Biochar is a substance formed of biomass – such as wood and crop waste, sewage sludge and paper waste – that is heated to 400-800°C under limited oxygen conditions to make a charcoal-like product. This can be then added to soil, where it not only stores carbon, but also interacts with microbes in the soils to improve their ability to capture additional nutrients and soil carbon.
Until now, however, biochar has received mixed results when tested for its effects on soils and crop yields.