Yields of four major crops were not rising fast enough to meet projected global demand in 2050, warns a study published today (June 20) in the journal PLoS ONE.
Several studies had shown that global crop production needed to double by the middle of this century to meet demands from an increasing human population, more meat and dairy consumption driven by growing affluence and more biofuels use as well to provide food security to millions who were chronically undernourished, observed Deepak K. Ray and his colleagues at the University of Minnesota's Institute on the Environment in the U.S..
Boosting crop yields, rather than clearing more land for agriculture, was the preferred solution to meet this goal, they pointed out.
The researchers used a newly-developed crop yield and area harvested database to examine yield changes across the globe in maize, rice, wheat and soybean, focusing on trends in the recent two decades.
These four crops together produce nearly two-thirds of the global agricultural calories.
Yields of these crops needed to grow at about 2.4 per cent annually to double production by 2050. But the global average yield increase was only 1.6 per cent a year for maize, one per cent for rice, 0.9 per cent for wheat and 1.3 per cent for soybean. At these rates, global production of the four crops would be “far below what is needed to meet projected demands in 2050,” they noted in the paper.
Moreover, the global trends masked significant variations in the rates of yield change among and within countries.
Yields were growing slowly in the top three rice and wheat producing nations. Rice yields had improved in China by only 0.7 per cent a year, in India by one per cent and in Indonesia by 0.4 per cent.
“At these rates, we found that yield driven production growth in India and China could result in nearly unchanged per capita rice harvests, but decline steeply in Indonesia.”
The yearly wheat yield increases in China, India and the U.S. amounted to only 1.7 per cent, 1.1 per cent and 0.8 per cent.
“Clearly, the world faces a looming and growing agricultural crisis,” said Dr. Ray and his colleagues in their paper.
However, they also pointed out that opportunities did exist to increase production through more efficient use of arable land and boost yields by spreading best management practices.
A portion of the production shortfall could be met by expanding croplands, but at a high environmental cost.
Additional strategies, particularly changing to more plant-based diets and reducing food waste, could reduce the large expected demand growth in food, they remarked.
