More water for life

Water is the life-blood of agriculture; it is the liquid elixir that nurtures the growth of billions of hectares of crops needed to feed the world. The ample supply of water for farming and agriculture often means the difference between feast and famine. Many parts of the world, however, suffer from the opposite - the growing scarcity of water available for agriculture. The reasons can range from drought and desertification to climate change and climate variability, pollution, over-use and poor water management practices.

Acutely aware of the seriousness of this problem, affected countries are implementing measures to ensure adequate water supplies for farming. Some of these measures involve the use of nuclear techniques to better understand, analyse and mitigate the root causes of the problem.

With technical help from the IAEA, countries from Africa, the Middle East and Asia are reporting successes in water resource management. Some notable examples:

In Libya, nuclear techniques helped identify proper "fertigation" management resulting in tremendous savings in water and fertilizer use. Fertigation is the process of applying fertilizers through a drip-irrigation system and can efficiently control the flow of water and nutrients to the roots of the plants. For Libya, this process helped increase potato yield by 150% and halved water and nitrogen use.

In Algeria, the fast rate of soil and water salinization drastically reduces the amount of arable land and contributes to desertification. This situation is most pronounced in the western part of the country, where 30% of the area consists of very saline soils and where there is a shortage of good quality water for irrigation. Using nuclear techniques, an IAEA-assisted project there is helping develop appropriate irrigation, drainage, soil and crop management practices so that preventive and corrective measures can be taken.

In Bangladesh, soil and water salinity along coastal areas where rice is planted is a continuing challenge. Sea water that flows inland along with the high tides spill over and salinizes soil and shallow ground water, particularly during post-harvest season when the rice fields are bare. Approximately 90% of the arable lands in the coastal areas have been salinized this way, resulting in extended fallow period - when the land is left uncultivated. To reduce this long fallow period and to improve farmers´ livelihood, it has been recommended to have another crop grown and harvested to improve food security.

Through an IAEA technical cooperation project, a new integrated technology that estimates soil, water content for timely introduction of brackish water to maximize intake by plants was tested. The project also introduced the use of isotopic techniques to assess the tolerance of different crops to different range of soil and water salinity during the fallow period. Using these techniques, Bangladeshi farmers were able to successfully plant salt-tolerant varieties of beans sesame, chickpeas, groundnuts and wheat on these fields immediately following the rice harvest. These crops boosted farmers' income during the off-harvest months and helped improve their livelihoods.

In China, scientist from 12 countries recently gathered to evaluate a range of range of conventional and isotopic techniques that can measure quantities of water lost to soil evaporation and plant transpiration, a process known as evapotranspiration (ET). With support form the IAEA and the Chinese government, the scientists conducted field tests in a maize field using both state-of-the-art laser technology, as well as low-level methods to measure ET under different irrigation management systems. The ability to partition ET into evaporation and transpiration components is important because it helps farmers find better and more efficient ways to use water by increasing transpiration and reducing evaporation. As the water available for agriculture becomes limited due to population growth, competition from other water users, drought and water quality degradation, it is important to ensure that every drop of water (either from rainfall and irrigation) is maximised for crop water use.

More info: www.iaea.org/

Provided by International Atomic Energy Agency