A New Way to Feed the World as Temperatures Soar
Turn over a packet of seeds and a custom set of instructions explains how you can grow whatever it is you’re looking to grow. Depending on what type of vegetable you’ve got your hands on, things such as the ideal depth and spacing of seeds will vary. Watermelon and squash plants, with their long, trailing vines, need a lot of room, while carrots and radishes are happy to grow in tighter clusters. Still, there’s one set of instructions that’s nearly always included: Seeds like to be planted in rich soil, and they should be regularly, evenly watered.
The problem is, in much of the world, those kinds of conditions aren’t always available. Soil is poor, and water is scarce. So if you live in a dry place—be it in rural Latin America or urban Los Angeles—what to grow? The choice is surely more fraught for a subsistence farmer living in Nicaragua than for a hobby gardener like me. But thanks to climate change, there’s a hotter, drier future ahead for us both, and the bean of choice could end up being somewhat the same: the so-called “heat-beater” bean.
On Wednesday, plant breeders from the agriculture research group CGIAR announced 30 new types of beans bred to withstand the kinds of harsh conditions expected to become the norm in Latin America and Africa by 2050. Four hundred million people rely on beans, a cheap form of plant-based protein, as an integral part of their diet in the developing world—but rising temperatures could cut the suitable range for growing beans by 50 percent, CGIAR’s Steve Beebe noted in a press release. While most bean varieties suffer lower yields when nighttime temperatures are above 65 degrees, these new varieties have been shown to withstand 72-degree overnight heat.
To develop the new beans, Beebe and his colleagues turned to teparies, a species native to the American Southwest and Northern Mexico and considered to be one of the most drought- and heat-tolerant crops in the world. There are documented cases of the beans being farmed in places that receive three inches of rain annually, and where temperatures hit 118 degrees. While they generally prefer a bit more rain, they can thrive in poor, alkaline soils that can be disastrous for other crops.
Recently, I ordered a packet of Colonia Morelos tepary beans from Native Seeds/SEARCH, a seed conservation nonprofit based in Tucson, Arizona. With the California drought now in its fourth year and temperatures climbing into the 90s in March, it’s hard to be both ecologically conscious and have a garden without operating something like a resource-poor farmer. Once the weather is more consistently warm, I plan to sow the multicolored seeds in the dry California dirt, cover them with mulch, water them once, and leave them be. That alone should be enough for the speckled seeds to germinate and grow into bushy vines, their white and lilac flowers eventually turning into seed pods full of protein-rich teparies.
There is, however, a difference between farming like it’s 2050 and farming like it’s 1050. If teparies were in and of themselves enough for bean farmers to beat climate change, the folks at CGIAR would not have spent 20 years, on and off, developing crosses between teparies and the common bean—which include black, kidney, pinto, and the like. The yields can be low, and the pods don’t ripen evenly, leaving some ready to harvest while others are still green. Ripe pods tend to shatter too, scattering beans over the ground—beans that, thanks to teparies’ quick germination, can turn into new plants before being gathered for food.
Unlike my tepary experiment, the new beans promise not only better yield but higher iron content—a hedge against the malnutrition that’s so common throughout the developing world. And all of this, mind you, has been achieved through traditional plant breeding.
Native Seeds/SEARCH sells an array of drought-adapted seeds, many of which have a long history of being farmed in the dry heat of Arizona and nearby states in Mexico: squash, tomatillos, wheat, corn, tomatoes. The Chimayo squash and Punta Banda tomatoes I’ll be growing alongside my Colonia Morelos teparies are unlikely to save the global food supply as broad swaths of the world become drier and hotter—but as CGIAR heat-beater beans suggest, they may offer a first step in the right direction.