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.
2018/07/26: almost 4.5 million people die each year from health problems caused by inhaling indoor smoke generated by burning solid fuel. Worldwide, 38 percent of the population – 2.7 billion people – cook with wood collected unsustainably from forest and farm landscapes.
In sub-Saharan Africa, the backbreaking process of gathering firewood by hand – often by women and girls – and carrying it home provides the main source of fuel for cooking and heating.
Although liquid fuels, solar energy and hydropower could offer possible alternatives, high costs, infrastructure shortcomings and local habits make sustainable use of wood fuel, including firewood and charcoal, a more viable option in the region.
As a result, researchers at the World Agroforestry Centre (ICRAF) and the Wangari Maathai Institute (WMI) in Nairobi, Royal Institute of Technology, Lund University, Swedish University of Agricultural Sciences, International Institute for Tropical Agriculture, Center for International Forestry Research are trying to find healthier, more efficient energy conversion technologies that emit less pollution and simultaneously produce biochar (biomass charcoal) for soil amendment to improve plant growth and health.
Not only is it strenuous work to gather wood, it detracts women from other pursuits such as agriculture or operating small businesses to generate income,” said Njenga. “Women spend about one working day per week in collecting firewood from forests. This implies that women are essentially living on a 20 percent pay cut as their productive days in a week are normally five as they spend Saturdays attending to domestic chores.”