Increasing water-scarcity brought on by over-exploitation and the effects of climate change is a key constraint on food production. The solution is improving water productivity – achieving ‘more crop per drop.’
Water scarcity is a constant and growing problem for dryland countries. The dry lands have less than eight percent of the world’s renewable water resources and are challenged by extreme temperatures, frequent drought, and desertification.
Across all dryland areas, scarce water availability is the key limiting factor for food production. Countries are suffering from severe groundwater depletion and salinity, compounded by rapid natural resource degradation. The Middle East and North Africa is the most water scarce region in the world, and the problem is set to deteriorate.
Famines and disasters have hit dry lands with increasing intensity and have, together with spikes in food prices, led to political unrest in many countries. With climate change, such events may become even more frequent.
Depletion and mismanagement of groundwater reserves is being exacerbated by the effects of climate change, with less rainfall, and more erratic distribution. Population growth, pollution, and increased salinity have compounded the problem, placing growing pressure on smallholder farmers in their quest for stable food production. The difficulties are becoming even more acute due to competing demands from rapidly increasing urban areas.
While water issues are recognized by national leaders as a strategic priority, however, very few countries have a master plan for managing water in their agricultural sector, and for dealing with the uncertainties that lie ahead.
Most countries are also relying on increasing the efficiency of irrigation systems to save water. But research has demonstrated that this alone will not solve the problem – countries will not have enough water to increase productivity sufficiently to achieve food security. Part of the solution will come from increasing water productivity – the return for a cubic meter of water.
Producing more with less: options for farmers
It takes one liter of water to produce one kilocalorie of food. This means that each person consumes 3- 4000 liters of water, just while eating. For that reason it is crucial to invest in water efficiency for food security.
Fortunately, our research and experience tells us that it is possible to produce more with less – with the correct application of scientific expertise and technology. Some of the options available include:
- Modernizing irrigation systems and enhancing water productivity
- Modifying cropping patterns to enhance water productivity
- Supplemental (targeted) irrigation
- Macro and micro water catchments
- Watershed management
- Deficit irrigation
Using water wisely: Supplemental irrigation, which allows farmers to plant and manage crops at the optimal time, regardless of climate vagaries, can significantly increase water productivity. Supplemental irrigation allows farmers to plant their crops early, increasing yields, and preventing exposure to terminal heat and drought stress in hot areas, and frost in cold areas.
Field trials in several countries have shown massive increases in wheat and barley yields with small quantities of supplemental irrigation: yield increased from 1.25 t/ha to 3 t/ha in Syria, from 4.6 to 5.8 t/ha in Morocco, and from 2.2 to 3.4 t/ha in Iran.
Water harvesting - conserving scarce water resources and adopting indigenous knowledge: Water harvesting is an effective, low-cost technology to conserve every last drop of available moisture. In the drylands, there is scope for harnessing traditional knowledge developed over generations by rural communities. Examples include underground cisterns, flood harvesting systems, and basins for collecting water and channeling it for household use and horticulture. Many dryland countries have a strong tradition of water storage. By building on these technologies, the resilience and adaptability of rural communities can be further strengthened.
‘Protected’ agriculture: ICARDA is promoting protected agriculture to overcome the harsh growing conditions that prevail across many dry land countries. It developed a suite of innovations, and adapted and optimized them into an integrated production system based in soilless culture to deliver higher yields of quality cash crops while reducing the use of water, fertilizers, and pesticides.
These innovations include improved greenhouse designs tailored to the regions with high temperatures; integrated pest management practices that reduce harmful pesticide use; and hydroponics production (soilless) systems with controlled water and plant nutrients for maximum productivity per unit water and land.