Nearly four years ago, researchers documented for the first time how farmer-led irrigation in sub-Saharan Africa and South Asia is transforming food security at an astonishing scale. They also showed that smallholder water management innovations hold potential to boost crop yields and household revenue by tens of billions of US dollars.
Since then, however, new research for development has revealed how small-scale irrigation may have benefits that reach far beyond food security alone.
Four ways to invest in smallholder irrigation
The research was initially carried out by the CGIAR Research Program on Water, Land and Ecosystems (WLE) and its partners under the AgWater Solutions project. At its conclusion, the project recommended four key areas that investments should focus on in order to unlock the potential of small-scale irrigation:
increasing access to water resources, including sustainable groundwater, small reservoirs and rainwater harvesting;
catalyzing smallholder value chains, removing information and marketing constraints;
creating policy synergies, such as aligned energy policies; and
taking a watershed perspective to reduce adverse environmental impacts.
Building on this work, WLE and USAID have supported research and development of business models that can operationalize these recommendations, while also exploring new solutions and creating a better understanding of potential additional impacts and benefits from investments in smallholder irrigation.
New technologies produce new opportunities and remove constraints
One new opportunity is solar pumps, which has only recently become a financially viable option for smallholder farmers. Solar power irrigation has taken off in India and is starting to take hold in sub-Saharan Africa, where solar powered pumps can serve as a more versatile, green alternative to motor pumps. The Africa Rising project, in collaboration with the International Water Management Institute (IWMI), has begun demonstrating solar powered pumps in two regions of Ethiopia.
A large, old Faidherbia albida tree with a metre-plus diameter stored the equivalent of the CO2 emitted by 8 cars over one year.These useful trees play an important role in carbon sequestration, a critical part of the effort to reduce greenhouse gas emissions linked to climate change.
People in many areas of Africa gain numerous benefits from the leaves, branches and trunks of the dryland thorn tree Faidherbia albida.
The tree’s spreading roots conserve the soil from wind and water erosion. Its roots fix atmospheric nitrogen which then passes to the leaves, which fertilize the topsoil when they fall, leading to higher crop yields.Faidherbia’s wide canopy provides shade as well as leaves and pods that serve as nutritious fodder for sheep and goats. And for people living around lakes, the trunk has light yet strong wood perfect for traditional dugout fishing canoes. The multipurpose tree is ideal forevergreen agriculture.
And now, carbon credits could join the list of benefitsFaidherbia albida brings to communities.
Research by World Agroforestry Centre (ICRAF) and partners, reported in a recent article in the journalAgroforestry Systems, has come up with formulae that allow us, for the first time, to accurately calculate the ‘total above-ground biomass’ of F. albida. This value indicates the amount of carbon sequestered by the tree. Working out the carbon stored in trees is the starting point for entering the global carbon credits markets, in which payments are based on the amount of the carbon in standing trees.
A plague of locusts fly above the road between Belo Tsiribihina and Morondava. Madagascar is battling its worst locust plague since the 1950s. People are going hungry, as the insects have destroyed so much of the island’s crops. Measures to fight the plague have been hampered by a lack of funds and poor organisation.
Yemen braces for locust ‘plague’
by Adel Aldaghbashy
Many juvenile locusts have matured into flying adults
Presence of vital honeybees limits insecticide control efforts
Any outbreak could go on to hit Oman, Saudi Arabia, the UAE and Iran
Yemen is bracing itself for a “locust plague” that scientists are unable to stop due to fears that any intervention would also kill bees that are vital to its economy.
The country’s Desert Locust Control Centre issued a warning on 18 April that many desert locusts in the country had reached their flying adult phase, while the remaining juveniles could do likewise in a matter of weeks.
The centre says control efforts this month, especially in the southern coastal province of Shabwah, have largely failed. Yemen is already struggling under the weight of civil war, which has made many affected areas unsafe.
“The intervention process to control locusts through insecticide spraying was very difficult due to a number of obstacles, the most important of which were the security aspect and the presence of beehives,” says Ahmed Al-Eryani, a spokesman for the centre. This is because pesticide spraying is likely to kill the bee populations crucial to the region’s agriculture and honey production, he explains.
Sub Saharan Africa is currently experiencing a food crisis due to drought. The World Food Program estimates that 10 million people in the region will require food aid in the coming year.
How can water resources be better used to ensure food security in these arid and semi arid areas?
One particularly promising way is to explore groundwater irrigation. It is a growing sector, and as surface water becomes more variable and uncertain, it provides an important buffer for farmers. It also responds to their water demand in a more flexible and reliable way, which would allow them to increase their yields and mitigate the effects of extreme water shortages.
An important vehicle to promote poverty alleviation, especially in rural areas, groundwater irrigation can provide much needed food, as well as rural employment. Crop yields in areas that are currently already using this resource, either solely or in combination with surface water, are typically much higher than those using surface water irrigation alone.
At the moment, groundwater is a largely untapped resource in sub-Saharan Africa, with only 1% of cultivated land being equipped for groundwater irrigation in all of Africa, as compared to 14% in Asia. There are sufficient groundwater stores in many parts of the continent so the potential to increase use for irrigation is quite high.
Ease of extraction and demand are uneven, however, and renewability of groundwater must be considered in order to make any groundwater irrigation schemes beneficial and sustainable over the long term. This requires a good estimation of upper limits for sustainable irrigation and most appropriate geographic areas for development.
The question then is: where does it make sense to develop renewable groundwater irrigation?
In the western United States, disputes over the management of the Klamath River, which wends its way from southern Oregon to the Pacific Ocean through northern California, have made blood boil for generations. Cattle ranchers and potato farmers want to take the water out for irrigation; Native American tribes, environmentalists, hunters and anglers want to leave it in to support fish and waterfowl populations. Every summer, tempers flare as the rain dries up and water levels begin to fall.
But until now, most global analyses would not have categorized the basin as experiencing “water scarcity” — a condition defined by the withdrawal of more water than is sustainably available. That’s because the analyses have been done on an annual basis, and it is only for three months of the year, in July, August and September, that water from the Klamath River is in short supply.