By Isaiah Esipisu
But care will need to be taken to ensure water is used widely and doesn't lead to shortages, experts say
UKUNDA, Kenya, Oct 31 (Thomson Reuters Foundation) - The power of irrigation is on full display in this corner of southeastern Kenya, where an 8,000-hectare sugarcane plantation glimmers in an otherwise semi-arid landscape.
Yields at the Kwale sugar plantation are higher than they would be if it relied only on rain, and there is no need to worry about variations in seasonal rainfall, said Pamela Ogada, general manager for Kwale International Sugar Company Ltd., which owns the site.
Across many parts of the world, irrigation has been a "magic bullet" in boosting harvests, said Nuhu Hatibu, the East African head of the Alliance for a Green Revolution in Africa (AGRA), which works to improve farming across the continent.
But irrigation is underused in sub-Saharan Africa, where just 7 percent of farmland is irrigated, the lowest proportion of any region of the world, according to the International Water Management Institute.
Now AGRA hopes to focus investment on bringing the technology to small-scale farmers - including those suffering worsening drought as a result of climate change.
The World Bank has pledged to work with the African Development Bank and other organisations to provide up to $9 billion to African governments to improve irrigation, said Steven Schonberger, the World Bank's global lead for water in agriculture.
Financing for the effort is still being put together, Schonberger said, but "we are very optimistic about it because a lot of financing is already there".
The money could begin to flow as soon as 2019, he said.
The cash could help governments carry out work such as improving mapping of aquifers in their countries, to understand where improved irrigation is possible and how much water is available, Hatibu said.
Such mapping is already underway in a range of African countries, including Ethiopia.
Hatibu said that, as part of the irrigation push, AGRA will launch a microfinance "irrigation fund" where businesses can seek loans to build irrigation infrastructure, from wells to pipes and water storage.
Rajiv Shah, the president of the Rockefeller Foundation, one of AGRA's funders, said boosting irrigation is key to improving agricultural productivity in Africa.
"Compared to any other agriculture-producing economy on the planet, Africa uses very little irrigation and very little fertiliser," he said.
But efforts to produce an agricultural Green Revolution in Africa - like ones that dramatically increased crop production in Asia and Latin America in decades past - should take into account worsening water scarcity and climate change, he said.
After decades of heavy irrigation that boosted yields in India, for instance, the country is now grappling with big declines in groundwater that threaten the sustainability of irrigated farming in some regions.
Preliminary findings from ongoing research funded by Britain's Department for International Development suggest that water tables in some African nations are already declining as irrigation and other demands on water grow, the researchers say.
In Ethiopia, for instance, competition is increasing for the shallow groundwater often used by small-scale farmers, said Behailu Berehanu, a hydrologist at the University of Addis Ababa and a contributor to the research.
"With the growing trends of water use for industry, community water supply, rapid urbanisation, (and) rapid growth of irrigated areas, definitely sustainability will be questionable," he told the Thomson Reuters Foundation.
"The main problem - and it cuts across many African countries - is that we do not have proper integrated groundwater ... management practices," he said.
Hatibu said efforts to scale up irrigation in Africa could benefit from technology and experience from other parts of the world aimed at using scarce water more efficiently.
That includes "well-balanced design of how much pumping is happening in relation to the recharge" of groundwater, he said, and efforts to help more water sink into the ground, to rebuild underground water stores.
Increased use of irrigation in Africa might also be powered with solar panels, to help rural communities gain greater access to power without producing more climate-changing emissions, Shah said.
The Rockefeller Foundation's "Smart Power" programme in India has helped communities set up solar mini-grids that, besides powering irrigation, have provided energy to set up agricultural processing plants, he said.
Some grids have also been able to sell power back to the national grid, bringing communities an additional source of income, he added.
(Reporting by Isaiah Esipisu. Editing by Laurie Goering. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, climate change, resilience, women's rights, trafficking and property rights. Visit http://news.trust.org/climate)