The world's major river basins may hold the key to doubling food production in the coming years. The idea was discussed at the 14th World Water Congress in Brazil.
A new report says while water shortages do exist around the world, water scarcity is not the major obstacle to producing more food. Rather, the report says, it's the "inefficient and inequitable distribution of the massive amounts of water that flow through the breadbaskets of key river basins."
Story to tell
These include the Nile, Ganges, Andes, Yellow, Niger and Volta. Dr. Simon Cook and his colleagues studied 10 major river basins in all. He said river basins have a story to tell.
"The first thing that they tell us is that there is quite massive unused capacity to produce more food without necessarily compromising the water resources," he said.
Cook was the coordinator for the Basin Focal Research Project for the Challenge Program on Water and Food.
"They tell us the major potential lies in rain-fed agriculture, not in irrigation. Although in Africa there is substantial scope for irrigation. They tell us that many of the problems are not problems of capacity. They're problems of the way that resource has been appropriated in, what you might call, an unbalanced way," he said.
Potent potential
River basins provide water, food, energy and biodiversity -- all things necessary for life. But Cook said these are often used inefficiently, especially water.
"If you look at the total amount of water going into river basins and the total amount of food coming out of river basins, the conversion ratio is pretty small, pretty low. And certainly in the African basins it was often 10 percent or even less of capacity. So, there immediately you can see that there's a huge potential to actually satisfy future food demands without necessarily compromising even more scarce water supplies," he said.
The river basin is much more than just the channel of water and adjacent land. Cook said the whole landscape should be included.
"Often when people think of river basins they only think what happens once the water actually gets into the channel. But certainly in African basins often the proportion of water that gets into the channel, that is what's called blue water, is a fraction of the total water going through the river basin system," he said.
A river basin has two types of water.
"Blue water is water, such as irrigation water, that goes into the river channel and is taken out or put in ponds or lakes or what have you. It's water that you can see. But the vast majority of water is what's called green water, which is rainfall actually. It falls on landscapes. It's used to produce food. It never actually gets into the river channel, but it's really important. And it's the major part of the total water balance in river basins," he said.
The Basin Focal Research Project report says if farmers are to take advantage of that green water, they need inputs, such as seeds, fertilizer and possibly mechanization. It says fertilizer is often very underused.
Making the most of river basins
Besides agriculture, river basins are also home to fisheries and livestock.
"Think of the livestock system as three parts. First of all, you're trying to find stuff for the animals to feed off. And then you're trying to keep the animal healthy and keep it fed throughout its life because you don't get anything out of it until it's mature and it's producing. And then you're trying to sell the products. Now, there are three components there that need to be put together for farmers to really benefit," said Cook.
The report says Africa has the biggest potential to increase food production. But there are large areas in Asia and Latin America where food production is currently 10 percent below their potential.
The 10 river basins studied include the Limpopo, Niger, Nile and Volta basins in Africa; the Andes and Sao Francisco in South America; and the Indus-Ganges, Karkheh, Mekong and Yellow river basins in Asia.
The 14th World Water Congress was held in Recife, Brazil from September 25 to the 29.