For solar technology projects to be successful, Burney said, just dropping in and giving people irrigation kits doesn't work. Communities need access to a water source and need to see the benefits of a project.

"You need the technology and management and the water access, all together," said Burney. "Our solar project incorporates all of that."

According to Burney, smallholders need not limit themselves to solar irrigation systems. "Solar is great if you have an unreliable fuel," she said. "But if you're someplace that's connected to the grid, an electrical pump would more economical."

"There are a lot of different solutions that involve many different kinds of water harvesting," Burney said. "Groundwater, rainwater, surface water, and there are a lot of places in the Sahel, like Niger, for example, where there are artesian wells." The Sahel is a transitional belt of grasslands between the Sahara Desert and the savannas further south.

Given the diversity of water resources in West Africa, Burney suggests that nongovernmental organizations and governments prioritize detailed hydrologic mapping in the region. Otherwise, the cost of geophysical surveys and finding water sources, especially unseen groundwater, could become an insurmountable barrier for farm communities.

"It needs to be really detailed, comprehensive, usable information that's out there for everybody to be able to take advantage of," she said.

Burney says that both of the benefits that farmers get from irrigation systems –growing outside of the rainy season and producing more diverse, profitable crops – are important for adapting to climate change.

"You can produce more value on less land in most cases and not be as beholden to the whims of the rainy season," she said. Having more disposable income also will reduce vulnerability to hunger and malnutrition. "Economic development can be a form of adaptation," she said.

Rosamond Naylor, director of Stanford's Center on Food Security and the Environment, and Sandra Postel of the Global Water Policy Project were collaborators on the project.