If you support less efficient agriculture, organic food or conventional food without science optimization, crop yields will not be enough to feed the population of 2050. It's the population bomb scare of the 1950s and '60s reborn a century later.

While American agriculture has dematerialized in the last few decades - we produce far more food on far less land - Europe and other countries have not kept pace. Due to that, crop yields worldwide won't increase quickly enough to support estimated global needs in 2050, according to the claims of a paper in PLoS ONE. 

Without setting aside more land for farming, that is.

Previous estimates have claimed that global agricultural production may need to increase 60 percent to meet increasing demands and provide food security. In the current paper, the scholars assessed agricultural statistics from across the world and found that yields of four key crops — maize, rice, wheat and soybean— are increasing 0.96 percent every year. At those rates, production of these crops would likely increase 38 percent by 2050, rather than the estimated requirement of 60 percent. The top three countries that produce rice and wheat were found to have very low rates of increase in crop yields.

Maps of observed rates of percent yield changes per year. Global map of current percentage rates of changes in (a) maize, (b) rice, (c) wheat, and (d) soybean yields. Red areas show where yields are declining whereas the fluorescent green areas show where rates of yield increase – if sustained – would double production by 2050. Credit and link: doi:10.1371/journal.pone.0066428.g002

"Particularly troubling are places where population and food production trajectories are at substantial odds," says research associate Deepak Ray from the Institute on the Environment (IonE) at the University of Minnesota, "for example, in Guatemala, where the corn-dependent population is growing at the same time corn productivity is declining."

 "Clearly, the world faces a looming agricultural crisis, with yield increases insufficient to keep up with projected demands," says IonE director Jon Foley, co-author on the study. "The good news is, opportunities exist to increase production through more efficient use of current arable lands and increased yield growth rates by spreading best management practices. If we are to boost production in these key crops to meet projected needs, we have no time to waste."

 Their analysis maps global regions where yield improvements are on track to double production by 2050 and areas where investments must be targeted to increase yields. The authors explain that boosting crop yields is considered a preferred solution to meeting demands, rather than clearing more land for agriculture.

Citation: Ray DK, Mueller ND, West PC, Foley JA (2013) Yield Trends Are Insufficient to Double Global Crop Production by 2050. PLoS ONE 8(6): e66428. doi:10.1371/journal.pone.0066428