KYOTO: Recycling wastewater, practising deficit irrigation and planting genetically-modified seeds that need less water are among ideas to help desert agriculture proposed at the Third World Water Forum.
How to make the desert bloom is a problem most pressing on arid countries in North Africa, Central Asia and the Middle East, where agriculture consumes 90 per cent of available water yet contributes just 10 per cent of the region’s gross domestic product.
“There is a need to change perspective and stop thinking about yield in terms of tonnage per hectare but in terms of kilogramme for cubic meter of water,” said Ismael Serageldin, a top World Bank official for agriculture research.
Supplemental techniques such as drip irrigation can increase productivity of a crop to 2.2 kilograms per cubic meter — compared to the 0.8 kilograms per cubic meter produced using traditional methods of irrigation, he said.
Crops that depend on rainwater, by contrast, produce only 0.3 kilograms per cubic meter of water.
To prepare a crop for supplemental irrigation, the planting season can be extended by one month, moved for example from November to October, to ensure that crops are well watered before the first frosts.
“Applying a little bit of water at the right time can make a huge difference,” said Theib Oweis, a researcher with the International Center for Agricultural Research in Dry Areas, or ICARDA, a leading innovator in the Middle East.
Oweis also supported the use of deficit irrigation, or using less water than a plant needs, in the Middle East. While the yield might be less, the productivity of a crop based on its use of water makes it more efficient, he explained.
ICARDA researchers were also working on intraspecies hybrids known as germplasms to, for example, grow chickpeas that can resist the winter, “because according to our studies, if we plant them only in winter and not in spring their yields double,” he said.
“We have to look more at water-efficient germplasms,” agreed Serageldin. “A lot of work needs to be done in that direction,” as well as in helping to rid crops of parasites.
Controversy over the use of genetically-modified organisms has hampered agricultural research, Serageldin said, pointing to the debate that has kept “golden rice,” a GM crop invented by Swiss researcher Ingo Potrykus, off the market.
The betacarotene-rich product aims to help populations deficient in iodine and Vitamin A — some 200 million people, he said, including 14 million children who are blind.
According to the International Rice Research Institute, Asian countries are in 2003 to be provided with the rice seeds for experimental field evaluation, but it will take up to four years before the product reaches farmers or is made available in local markets.
More attention should also be paid to wastewater recycling for agriculture, a practice used in Israel, Australia and the Canary Islands, suggested Israeli researcher Avner Adin of the Hebrew University of Jerusalem.
“Water reuse has a lot of advantages” once heavy metals are filtered out, he said.
“Not only do you purify wastewater for agriculture purposes but you also prevent groundwater pollution.”
With the slow but inexorable creeping of desertification, now is the time for arid regions to change not only agricultural but cultural habits, other researchers noted.
In Central Asia, for example, livestock is set loose to graze on seedlings, eroding the soil and removing young plants that could eventually feed humans.—AFP