Much has been written about why eating more red meat could be bad for your health while also harming the environment. But new studies to be discussed at the 22nd International Grasslands Congress in Australia next week show that the scientists might be able to overcome the environmental impact of higher numbers of meat eaters and milk drinkers.
Scientists have been predicting that a growing demand for meat and dairy products will lead to more deforestation, which will increase the harmful carbon dioxide released into the atmosphere as pastures are expanded and more land is devoted to sowing crops to feed the burgeoning population of animals reared for their meat and dairy products.
More animals will also mean rising emissions of warming gases such as methane directly from the livestock, and nitrous oxide from the fertilizers, manure and other animal waste. Both these gases are extremely harmful as their capacity to warm the atmosphere is far greater than carbon dioxide. . . .
Secrets in the grass
But evidence has been mounting that a chemical mechanism operating in the roots of a tropical grass used for livestock feed holds enormous promise for reducing the emission of nitrous oxide, which has a global warming potential 296 times that of carbon dioxide and is the most harmful of the warming gases.
The mechanism is known as “biological nitrification inhibition,” or BNI, said Michael Peters, who leads research on forages at the International Center for Tropical Agriculture (CIAT), based in Colombia. CIAT is a member of the Consultative Group on International Agricultural Research (CGIAR) Consortium.
Peters told IRIN the grass belongs to the Brachiaria species commonly found in east and central Africa and is native to the region. Animals that consume the grass produce higher yields of milk and their manure emits smaller amounts of nitrous oxide.
”A maize crop grown after planting a certain type of Brachiaria grass produces a respectable yield while using only half the usual amount of nitrogen fertilizer…”
“Livestock production provides livelihoods for a billion people, but it also contributes about half of agriculture’s greenhouse gas emissions,” Peters explained. “BNI is a rare triple-win technology that’s good for rural livelihoods as well as the global environment and climate..."
Though Brachiaria grasses originated in Africa they are now planted more widely in South America. Peters told IRIN that breeding lines produced by CIAT have been brought back to Africa but currently cover no more than 10,000 hectares and involve only a few thousand farmers.
Eminent scientists like P[hilip] Thornton from the International Livestock Research Institute have also been calling for regulations for better management of animal waste in the developing world, which could reduce the emission of nitrous oxide.
Read the whole article at IRIN: Grass could tame global warming gases, 13 Sep 2013.