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Prickly pear to the rescue

Mostly powered by photovoltaic solar energy, our German Sister-City, Teterow, also generates a portion of its energy in a city owned and operated, combined heat and power bio-gas plant.
This facility converts to gas, through anaerobic bacterial fermentation, the organic “biomass” supplied by nearby farmers. These gain long-term contracts for their crops, mostly corn, and for fertilizer from processed residue from the facility. The city gains electric and heating power from the purified gas.
Yet extreme weather effects under changing climate are a looming threat to food production.
If climate change is not arrested soon, a recent report from a UK research center on Global Food Security warns, “the forecast for food looks grim.” Thus, to grow crops for energy, in fertile and rain-fed agricultural areas as around Teterow, may become a luxury humanity cannot long afford.
An entrepreneurial engineering professor at Oxford University is banking on desert plants to help power the planet without upsetting food supplies.
As per the title of an interview article on his research, published in New Scientist, the Prickly Pear (and a few other wild plants) would play a big role in such a “rescue” endeavor.
This ground hugging, woody plant is a member of the cactus family. As the only cactus native to Tennessee, it can be seen in Jonesborough’s Ardinna Woods Arboretum. Its fleshy stem pads come with a few long spines but many tufts of short, skin-penetrating bristles.
May and June are its usual bloom time for brilliantly yellow-petaled flowers, which have reddish centers and masses of pollen producing stamens, but an occasional blossom can be seen as late as September.
Like other cacti, Opuntia humifusa as it’s called in botanical nomenclature, has unusual characteristics that make it promising for the role envisioned by the scientist, Mike Mason.
It can grow fast in areas where food crops can’t grow.
It produces a lot of biomass through a trick lacking in conventional plants. These need more water since they “lose loads of [it] to evaporation.” The water loss occurs as they open their leaf stomata during daylight to take in carbon dioxide for photosynthesis.
Prickly Pear gets around this by capturing CO2 during the cool of night and holding it in the stem tissue for photosynthesis after sun up. Its inconspicuous, tiny leaves fall soon after they are formed, their role in food manufacture performed by the green-skinned, succulent stem pads. It thus gets by with at most a tenth of the water needed by conventional plants to produce the same amount of biomass.
Some 300 million hectares of semi-arid, little-used land could grow these plants. From ongoing research results in Kenya, Mason suggests, through bio-gas fermentation they “could in theory generate as much electricity as now produced globally from burning natural gas.” And, given low emissions in the biomass-to-energy projects he is studying, they could “keep serious amounts of carbon out of the atmosphere,” thus helping to curb the very climate-change effects which threaten future global food security.
Quite a feat for little-known Prickly Pear.