Study says existing cropland could feed billions more
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WASHINGTON, July 23, 2014 - A University of Minnesota (UM) research team says it has identified some relatively simple steps that can be taken to not only insure food security for a global population that is expected to soar to more than 9 billion people by 2050, but also reduce agricultural emissions that contribute to climate change.
An analysis from the university's Institute on the Environment identifies what the authors say are key “global leverage points” that offer the best opportunities to improve both global food security and environmental sustainability. They say that a relatively small set of places and actions could provide enough new calories to meet the basic needs for more than 3 billion people, address many environmental impacts with global consequences, and focus food waste reduction on the commodities with the greatest impact on food security.
“Fortunately, the opportunities to have a global impact and move in the right direction are clustered,” said lead author Paul West, co-director of the Institute's Global Landscapes Initiative. “By focusing on areas, crops and practices with the most to be gained, companies, governments, NGOs and others can ensure that their efforts are being targeted in a way that best accomplishes the common and critically important goal of feeding the world while protecting the environment.”
Published last Friday in the journal Science, the report focuses on 17 crops that produce 86 percent of the world's plant calories and account for most irrigation and fertilizer consumption on a global scale. The authors say the biggest opportunities cluster in high food producing nations and regions like the United States, China, India and Brazil, along with Europe.
A major field of opportunity, the report says, comes from producing more food on existing land. Researchers say previous investigations show the presence of a dramatic agricultural “yield gap” - the difference between potential and actual crop yield - in many parts of the world. The UM study found that closing even 50 percent of the gap in regions with the widest gaps could provide enough calories to feed 850 million people. Nearly half of the potential yield gap gains are in Africa, with most of the rest represented by Asia and Eastern Europe.
A somewhat related area of opportunity cited by the UM researchers is to grow crops more efficiently. The study identified where major opportunities exist to reduce climate impacts and improve the efficiency with which farmers use nutrients and water to grow crops.
Studies show that agriculture is responsible for 20 to 35 percent of global greenhouse gas (GHG) emissions. Yet the Minnesota study also notes that agriculture offers some solutions to the challenge of reducing GHG emissions, including efforts to stem carbon dioxide emissions from deforestation in Brazil and Indonesia, methane from rice production in China and India, and nitrous oxide from better managed crop fertilization in China, India and the United States.
UM researchers say they found that worldwide, 60 percent of nitrogen and nearly 50 percent of phosphorus applications exceed what crops need to grow. China, India and the U.S. -- and three crops: rice, wheat and corn - are the biggest sources of excess nutrient use worldwide and, as a result, offer the greatest opportunity for improvement.
U.S. agriculture groups, long sensitive to charges of ignoring food production's contributions to growing emissions, counter that the sector has long been engaged in finding ways to make production more efficient and cleaner, with fewer emissions. The National Corn Growers Association told Congress that since 1980, the amount of GHG emissions associated with growth of a bushel of corn has dropped by 36 percent.
Farm advocates also cite a 2012 study from Stanford University that found that advances in high-yield agriculture from 1961 through 2005 have prevented the equivalent of 590 billion metric tons of carbon dioxide from entering the atmosphere.
The UM analysis said more calories can be made available for human consumption by shifting crops from livestock to humans - a long-proposed notion that does not sit well with U.S. animal producers. The researchers say the crop calories currently fed to animals worldwide are sufficient to meet the calorie needs of 4 billion people, with corn said to be the main crop being diverted to animal feed.
But the analysis also recognizes that cultural preferences and politics limit the ability to change this picture. Still, the authors say, shifting crops from animal feed to human food could serve as a “safety net” when weather or pests create shortages is a valuable strategy to keep.
Finally, the UM authors note that some 30 to 50 percent of food is wasted worldwide. They cite as particularly significant the impact of animal products, noting the loss of 1 kilogram of boneless beef has the same effect as wasting 24 kilograms of wheat due to inefficiencies in converting grain to meat. The authors say reducing waste in the United States, China and India alone could yield food for more than 400 million people.
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