Cactus pears show great potential for sustainable food and fuel

Cactus pears could become a source of sustainable food and fuel in places that need these resources the most, according to the University of Nevada, Reno.

The fact that the plants are also heat and drought resistant, and not to mention capture carbon from the atmosphere, means that cactus pears could serve as an important crop in the face of climate change.

Climate projections show that long-term droughts will increase in duration and severity, which will lead to higher temperatures and less water availability. Crops such as rice, corn, and soybeans have an upper temperature limit, while other traditional crops like alfalfa require more water.

“Dry areas are going to get dryer because of climate change,” said Professor John Cushman. “Ultimately, we’re going to see more and more of these drought issues affecting crops such as corn and soybeans in the future.”

In a previous study funded by the Experiment Station and the U.S. Department of Agriculture’s National Institute of Food and Agriculture, Professor Cushman’s team conducted the first long-term field trial of Opuntia species. They found that plants including the spineless cactus pear could be used as raw material for biofuels to replace fossil fuels.

The study showed that cactus pears had the highest fruit production while using up to 80 percent less water than some traditional crops.

“Maize and sugar cane are the major bioenergy crops right now, but use three to six times more water than cactus pear,” said Professor Cushman. “This study showed that cactus pear productivity is on par with these important bioenergy crops, but use a fraction of the water and have a higher heat tolerance, which makes them a much more climate-resilient crop.”

The cactus pear is a versatile perennial crop that works well as a bioenergy crop. The plant also serves as a land-based carbon sink that captures and stores CO2 from the atmosphere. 

“Approximately 42% of land area around the world is classified as semi-arid or arid,” said Professor Cushman. “There is enormous potential for planting cactus trees for carbon sequestration. We can start growing cactus pear crops in abandoned areas that are marginal and may not be suitable for other crops, thereby expanding the area being used for bioenergy production.”

The study is published in the journal GCB-Bioenergy.

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By Chrissy Sexton, Earth.com Staff Writer