Climate change may expand suitable cropland, particularly in the Northern high latitudes, but tropical regions may becoming decreasingly suitable, according to a study published September 17, 2014 in the open-access journal PLOS ONE by Florian Zabel from Ludwig Maximilians University, Germany and colleagues.
Most of the Earth's accessible agricultural land are already under cultivation. Ecological factors such as climate, soil quality, water supply and topography determine the suitability of land for agriculture. Climate change may impact global agriculture, but some regions may benefit from it. In a new study, researchers focused on the probable impact of climate change on the supply of land suitable for the cultivation of the 16 major food and energy crops worldwide, including staples such as maize, rice, soybeans and wheat. They simulated the impact of climate change on agricultural production over the course of the 21st century and found that two-thirds of all land potentially suitable for agricultural use is already under cultivation.
The results indicate that climate change may expand the supply of cropland in the high latitudes of the Northern hemisphere, including Canada, Russia, China, over the next 100 years. However, in the absence of adaptation measures such as increased irrigation, the simulation projects a significant loss of suitable agricultural land in Mediterranean regions and in parts of Sub-Saharan Africa. The land suitable for agricultural would be about 54 million km2 -- and of this, 91% is already under cultivation. "Much of the additional area is, however, at best only moderately suited to agricultural use, so the proportion of highly fertile land used for crop production will decrease," says Zabel. Moreover, in the tropical regions of Brazil, Asia and Central Africa, climate change will significantly reduce the chance of obtaining multiple harvests per year.
"In the context of current projections, which predict that the demand for food will double by the year 2050 as the result of population increase, our results are quite alarming. In addition, one must consider the prospect of increased pressure on land resources for the cultivation of forage crops and animal feed owing to rising demand for meat, and the expansion of land use for the production of bioenergy," says Zabel.
The Future of Global Agriculture May Include New Land, Fewer Harvests
Two down, one to go. Researchers have completed the second of three major steps needed to turbocharge photosynthesis in crops such as wheat and rice, something that could boost yields by around 36 to 60 percent for many plants. Because it’s more efficient, the new photosynthesis method could also cut the amount of fertilizer and water needed to grow food.
Researchers at Cornell University and Rothamsted Research in the United Kingdom successfully transplanted genes from a type of bacteria—called cyanobacteria—into tobacco plants, which are often used in research. The genes allow the plant to produce a more efficient enzyme for converting carbon dioxide from the atmosphere into sugars and other carbohydrates. The results were published Wednesday in the journal Nature.
Scientists have long known that some plants are much more efficient at turning carbon dioxide into sugar than other plants. These fast-growing plants—called C4 plants—include corn and many types of weeds. But 75 percent of the world’s crops (known as C3 plants) use a slower and less efficient form of photosynthesis. Researchers have been attempting for a long time to change some C3 plants—including wheat, rice, and potatoes—into C4 plants. The approach has been given a boost lately by novel high-precision gene-editing technologies that are being applied to the C4 Rice Project (see “Why We Will Need Genetically Modified Foods”).
The Cornell and Rothamsted researchers took a simpler approach. Rather than attempting to convert a C3 plant into a C4 plant by changing its anatomy and adding new cell types and structures, the researchers modified components of existing cells. “If you can have a simpler mechanism that doesn’t require anatomical changes, that’s pretty darn good,” says Daniel Voytas, director of the Center for Genome Engineering at the University of Minnesota.
Turbocharging Photosynthesis to Feed the World
