A new study by Stanford University scientists has determined that solar-powered drip irrigation systems significantly enhance household incomes and nutritional intake of villagers in arid sub-Saharan Africa.
The two-year study found that solar-powered pumps installed in remote villages in the West African nation of Benin were a cost-effective way of delivering much-needed irrigation water, particularly during the long dry season.
"Significant fractions of sub-Saharan Africa's population are considered food insecure," according to lead author Jennifer Burney, a postdoctoral scholar with the Program on Food Security and the Environment and the Department of Environmental Earth System Science at Stanford.
"Across the region, these food-insecure populations are predominantly rural, they frequently survive on less than 1 dollar per person per day, and whereas most are engaged in agricultural production as their main livelihood, they still spend 50 to 80 percent of their income on food, and are often net consumers of food," she added.
Burney and her co-authors noted that only 4 percent of cropland in sub-Saharan Africa is irrigated, and that most rural, food-insecure communities in the region rely on rain-fed agriculture, which, in places like Benin, is limited to a three- to six-month rainy season.
Promotion of irrigation among small landholders is therefore frequently cited as a strategy for poverty reduction, climate adaptation and promotion of food security, according to the researchers.
For the research, Burney and her colleagues monitored three 0.5-hectare (1.24-acre) solar-powered drip irrigation systems installed the Kalale district of northern Benin.
The systems, which use photovoltaic pumps to deliver groundwater, were financed and installed by the Solar Electric Light Fund (SELF), a nongovernmental organization.
The three solar-powered irrigation systems supplied on average 1.9 metric tons of produce per month, including tomatoes, okra, peppers, eggplants, carrots and other greens, the authors found.
Woman who used solar-powered irrigation became strong net producers in vegetables with extra income earned from sales - significantly increasing their purchases of staples and protein during the dry season, and oil during the rainy season.
"Vegetable consumption increased during the rainy season (the time of greatest surplus for the women's group farmers) for the entire four-village sample of households," the authors said.
In terms of nutrition, vegetable intake across all villages increased by about 150 grams per person per day during the rainy season.
"Overall, this study thus indicates that solar-powered drip irrigation can provide substantial economic, nutritional and environmental benefits," the authors said.