The End of the Green Revolution
Green Revolution refers to a series of research, development, and technology transfer initiatives, occurring between the 1940s and the late 1970s, that increased agriculture production around the world, beginning most markedly in the late 1960s. It forms a part of the neo-colonial system of agriculture wherein agriculture was viewed more of a commercial sector than a subsistence one. The Green Revolution has since stagnated for key food crops in many regions of the world, according to a study published in the Dec. 18 issue of Nature Communications by scientists with the University of Minnesota’s Institute on the Environment and McGill University in Montreal, Canada.
Led by IonE research fellow Deepak Ray, the study team developed geographically detailed maps of annual crop harvested areas and yields of maize (corn), rice, wheat and soybeans from 1961 to 2008. It found that although virtually all regions showed a yield increase sometime during that period, in 24 to 39 percent of the harvested areas (depending on the crop) yield plateaued or outright declined in recent years. Among the top crop-producing nations, vast areas of two of the most populous — China and India — are witnessing especially concerning stagnation or decline in yield.
Cereal production more than doubled in developing nations between the years 1961—1985. Yields of rice, maize, and wheat increased steadily during that period. The production increases can be attributed roughly equally to irrigation, fertilizer, and seed development, at least in the case of Asian rice. The Green Revolution can be credited with saving over a billion people from starvation.
"This study clearly delineates areas where yields for important food crops are stagnating, declining, or never improved, as well areas where yields are still rapidly improving," Ray says. "As a result, it both sounds the alert for where we must shift our course if we are to feed a growing population in the decades to come, and points to positive examples to emulate."
Interestingly, the researchers found that yields of wheat and rice — two crops that are largely used as food crops, and which supply roughly half of the world's dietary calories — are declining across a higher percentage of cropland than those of corn and soybean, which are used largely to produce meat or biofuels.
"This finding is particularly troubling because it suggests that we have preferentially focused our crop improvement efforts on feeding animals and cars, as we have largely ignored investments in wheat and rice, crops that feed people and are the basis of food security in much of the world," said study co-author and IonE director Jonathan Foley. "How can we meet the growing needs of feeding people in the future if one-third of our cropland areas, in our most important crops, are not improving in yield any more?"
Without continuing Green Revolution efforts the Malthusian predictions of overpopulation resulting in famine may come true.
The paper suggests two actions based on its findings. First, it recommends working to maintain the positive trajectory for the 61 to 76 percent of croplands where yield is still climbing. Second, it encourages crop-producing regions around the world to look at their yield trends and those of others to identify what’s working and what might be improved.
For further information see Green Revolution.
Figure image via Deepak Ray, Institute on the Environment from University of Minnesota.