In the semi-arid Sahel region of Segou in central Mali, small-holder farmers often struggle to provide enough food for the area’s growing population, and rainfall pattern changes due to climate change are acerbating their hardship. The IAEA is working with scientists in this region to improve food security using climate-smart agricultural techniques to enhance water management and improve soil fertility. Since 2014, the IAEA, in partnership with the Food and Agriculture Organization of the United Nations (FAO), has provided expert advice, laboratory and field equipment and consumables on the use of nuclear and isotopic techniques to track fertilizer and water use efficiency. Participating farmers have reported a 37% increase in crop yield and a 43% reduction in water use for irrigation.
The 500 small-holder farmers, mostly women, have turned previously low-yielding lands into fertile agricultural plots, said Justin Diallo, Head of the Statistical Office, Monitoring, Evaluation and Communication at the Regional Directorate of Agriculture in Ségou.
“The producers faced a water problem, especially during the dry season. With the installation of this new system and the training they received, they learned to better manage the water requirements of crops,” he said. “Tomato cultivation, once abandoned, is now making a comeback.”
Small-holder farming provides over 70% of the vegetables available on the market in the region. Crop yields are dependent on the fertilization and moisture of the soil, which is often poor in nitrogen. Compared to larger and more developed farms that have access to irrigation systems and fertilizer, most small-scale producers lack the capacity, infrastructure and funding to cope with the erratic weather patterns caused by climate change. Often, they require expert support on sustainable cultivation and to alter soil management methods that contribute to accelerated soil degradation and salinization. To help them improve their practices and conserve resources, scientists are using isotopic techniques to determine how much nitrogen and water are taken up by the plants, so that the right amount can be added at the right time to enhance the production of high-value crops.
The absorption of fertilizers by crops varies depending on the crop and the type of soil. Nitrogen is a component of chlorophyll, the compound responsible for photosynthesis, which is the process by which plants convert sunlight energy into chemical energy. The IAEA, through its technical cooperation programme, has trained more than 50 Malian Malian scientists in using fertilizers labelled with the stable isotope 15N (nitrogen-15; nitrogen atoms with an extra neutron) helping them track nitrogen pathways in crops to determine the efficiency of fertilizer absorption. This helps to optimize fertilizer use by farmers.
In addition, the team of Malian scientists has been trained on how to use a soil moisture sensor to measure the amount of water in the soil and calculate crop water requirements. The team was also provided 15N-labelled fertilizer to quantify fertilizer use efficiency. . They also worked with the FAO’s AquaCrop model to simulate crop response to water. “There is a huge interest in this system, which has given visible and concrete results,” Diallo said.
“The participants transfer the knowledge to assist local farmers to improve the water- and nutrient-use of high-value crops. This multiplication of knowledge has had profound effects on local communities in Mali. The analysis of soil water can support the decision to establish appropriate irrigation systems to deliver small amounts of water directly to crops with precision,” explained Daba Coulibaly, who has been coordinating the project at the National School of Engineering (ENI-ABT) in the Malian capital of Bamako. “As a result of moving from manual watering to drip irrigation and the assurance of a constant supply of water from a borehole with a pump, combined with the timely application of fertilizer, farmers were able to increase yields from 46 to 63 tons per hectare – a 37% growth.”
Furthermore, a 43% reduction in water use for irrigation was also achieved, data collected from the farmers show. The water saved was vital for livestock farming, further improving food security and farmers’ earnings, Coulibaly added.
The project is building on its initial success and a partnership was established with the organization Sahel21, a collaboration of the University of Ségou and Mali’s Institute of Rural Economy (IER), to further expand this drip irrigation initiative to benefit hundreds more small-holder farmers.
“The overall goal is to build sustainable agricultural capacities across Mali to adapt to climate change, ensure greater crop yields for the Malian population, minimize land degradation and improve living standards,” said Lee Kheng Heng, Head of the Soil and Water Management and Crop Nutrition Section at the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture.
