By upcycling biomass, innovators aim to reduce greenhouse gas emissions and improve the economic viability of farming
When we pick up a piece of fruit, bar of chocolate or package of flour, we don’t often think of the massive amounts of agricultural waste — the stems, leaves, seed pods and more — that never make it off the farm.
Yet the scale of agricultural waste is huge. Globally, crop residues — the plant waste left in the field after harvest — totaled 5 billion metric tons (5.5 billion tons) in 2013, according to a 2018 Brazilian study. A study from South Africa reported that crop residues retained in the field are responsible for 13% of agricultural greenhouse gas emissions.
Some of that material is used for organic fertilizer, soil enrichment or animal feed. But plenty is still available for other uses.
Meanwhile, farmers are facing increased economic uncertainty due to climate change, leading to increased rural migration, according to a 2018 report from the United Nations Food and Agriculture Organization.