Scientists have discovered that a tropical grass used for animal feed may have enormous potential to reduce greenhouse gas emissions from agriculture.
A series of papers are set to be presented in Australia this week on how to exploit a phenomenon known as biological nitrification inhibition (BNI), a chemical mechanism that markedly reduces the conversion of nitrogen applied to soil as fertiliser into nitrous oxide.
Nitrous oxide is one of the most powerful and aggressive greenhouse gases, with a global warming potential of around 300 times that of carbon dioxide. It makes up about 38 per cent of all greenhouse gas emissions in agriculture, which accounts for almost a third of total emissions worldwide.
Research has shown that Brachiaria
grasses, originally from sub-Saharan Africa but now widely grown on pasturelands in Brazil, Colombia, and other countries as animal feed, capture large amounts of atmospheric carbon. This means they need only half the amount of nitrogen fertiliser because they retain more nitrogen in the soil.
And scientists have now found a way to increase BNI through plant breeding in different species of Brachiaria
, potentially reducing nitrous oxide emissions and nitrate leaching.
Michael Peters, who leads research on forages at the Colombia-based International Center for Tropical Agriculture (CIAT), said BNI could be "agriculture's best bet" for keeping global climate change within manageable limits.
''livestock production'' provides livelihoods for a billion people, but it also contributes about half of agriculture's greenhouse gas emissions," he added. "BNI is a rare triple-win technology that's good for rural livelihoods as well as the global environment and climate. It defies the widespread notion that livestock are necessarily in the minus column of any food security and environmental calculation."