Nonfood crops lock up enough calories to
feed 4 billion
Global calorie
availability could be increased by as much as 70 per cent — feeding an
additional 4 billion people — by shifting cropland use to produce food for
humans rather than livestock feed and biofuels, according to new research.
Such a shift could free
up calories roughly equivalent to the yield increases achieved for maize, wheat
and rice between 1965 and 2009, researchers say in the study, published in
Environmental Research Letters this month (1 August).
"When talking about the future of food security, people often suggest that we grow our way out of the problem: that if we just keep producing more corn and soybeans we will be able to feed the world.
Our study provides an
alternative point of view," Emily Cassidy, lead author of the study and
environmental scientist at the University of Minnesota, United States, tells
SciDev.Net.
Researchers looked at
the 41 crops that provide more than 90 per cent of world's calories. They
analysed where the crops are grown, the overall production and also how the
crops are used: for direct human consumption, animal feed or biofuels.
"Globally, 36 per
cent of all calories are fed to animals. We found that decreasing grain-fed
meat consumption by 50 per cent would be enough additional calories for two
more billion people," says Cassidy.
Reducing meat
consumption, or shifting it away from beef to poultry and pork, has the potential
to feed more people per hectare of cropland because beef is not energy
efficient, Cassidy adds.
"When we feed 100
calories of average corn and soy to beef cattle we get only three per cent of
these calories back, while the efficiency is better for pork and
chickens," she says.
Researchers also looked
at crop allocation in terms of proteins.
"Half of the
protein that we produce with crops actually goes to animals for feed. We could
have the right amount of protein and amino acids if we were to directly consume
crops," says Cassidy. "We are actually losing a lot of protein in the
plant-animal conversion process."
Yet, the authors
recognise that the recent global trends are towards more meat consumption and
biofuel production.
"Meat is part of
the human culture and it's important for food security in many parts of the
world, but when we increase crop yields in affluent nations we are just feeding
animals and this is not turning into much food for human consumption,"
says Cassidy.
Read more at SciDevNet.