Water trickles out of a tiny black plastic tube and flows onto a spot near a young banana plant. The set-up looks simple, but it works with precision. The tube delivers just the right amount of water, at a specific time to a precise spot from where the water will be best absorbed by the plant. This is the set-up for drip irrigation.
The location - a small test field in a greenhouse of the IAEA´s Laboratories Seibersdorf. This field contains three rows of about 30 banana plants and flexible plastic tubes that are perforated at certain intervals to deliver irrigation water run alongside the plant rows. A red box sits in the centre of the field is a neutron probe - an instrument which uses nuclear technique to measure the quantity of water in the soil.
Here, a team of IAEA´s scientists are working on perfecting drip irrigation for different types of plants. They then transfer the knowledge to the scientists in member States who will then work with the Agency or by themselves to transfer the technology and information know-how to the farmers across the world.
Why Drip Irrigation?
Agriculture is the largest freshwater consumer using more than 70% of the available freshwater. An ever-expanding population that not only demands a greater share but also more food means we need to grow more crops by using less water.
But the freshwater resources are shrinking rapidly and the water quality is declining. Water is polluted with sediments, fertilizers and pesticides that leach out from the fields due to traditional irrigation methods and poor soil management.
"Today, saving freshwater is as much about quantity as about quality," says Long Nguyen, Head of the Soil and Water Management and Crop Nutrition Section, a programme run jointly by the FAO and IAEA.
Nguyen, who has been working in soil and water management for decades, stresses that now, more than ever before, it has become imperative to use water-saving methods like drip irrigation and encourage more farmers to adopt the technique.
Success Story from Turkey
"Drip irrigation is one of the best ways to achieve the more crop per drop endeavour," he says.
The aim is to squeeze every bit out of every drop while ensuring that the existing water resources are not polluted. And Nguyen says that drip irrigation has proven very successful in both regards. "In Turkey, potato farmers were able to reduce the amount of water required for irrigation by 50 percent," says Nguyen.
Lee Heng, soil scientist at IAEA´s Soil and Water Management and Crop Nutrition Section and Michel Warnau, programme officer in the IAEA´s Department of Technical Cooperation have been taking the technology out to the fields in Africa. They talk about their on-field experiences in some of the African countries including Algeria, Libya, Kenya, Mali, Niger and Turkey.
"We noticed that because the water is targeted directly to the roots, the leaves and stems are not in contact with water and the crops are much less prone to fungal diseases," says Heng.
"Moreover, drip irrigation not only reduced the quantity of water required, but also improved the water quality of the surrounding water bodies," Heng stresses. When methods like surface or sprinkler irrigation were used, excess water seeped below the rooting zone into the groundwater table taking with it dissolved fertilizers and pesticides, explains Heng. "With drip irrigation this problem was completely solved," she says.
But how is the technology transferred to farmers? "Transferring this drip technology to the fields requires good communication with the farmers," says Warnau. "Under laboratory conditions and field research stations, we can test the effectiveness of drip irrigation by seeing how much water a particular type of soil can hold and also use nuclear techniques to see if the crops are actually absorbing the water that is provided. Then, through the IAEA´s network in different member states, the end results are communicated to the farmers," he adds.
Is drip irrigation a new concept then? "No," says Long. "It has been around for many years. But now, by using nuclear science techniques at IAEA laboratories, we have carried out studies and have results and scientific proof that the system helps farmers to use water efficiently, significantly cutting farming costs and improving crop and water quality," says Long.
"Seeing is believing," says Joseph Adu-Gyamfi, a soil scientist working at Seibersdorf, "that is why we have ´champion farmers´ who are effectively using drip irrigation and spreading the word in their community."
Nineteen African countries are now part of the IAEA´s technical cooperation project that aims to promote drip irrigation for high-value crops. The team says that results it has got from the fields are impressive and it is working to spread the "more crop per drop" message in the farming community across the world.