Nuclear technology quantifies and guides efforts to combat climate change
The Joint FAO/IAEA Division is at the forefront of efforts to develop and validate sensitive and specific nuclear and nuclear-related techniques that are simple to use and provide efficient and cost-effective ways to enhance or advance the development of integrated agricultural systems. The following identifies three main areas where the Division has taken the lead in developing and disseminating appropriate supportive technologies.
Soil management. Nuclear applications in soil, water and crop nutrition management can enhance crop adaptation and flexibility in areas that face the highest threats from changing climates. The nuclear techniques that improve soil management and thus contribute to mitigating impacts of climate change are based on the use of radionuclides or stable isotopes of carbon and nitrogen. For example, erosion and sedimentation can be assessed by monitoring radionuclides, which are widely distributed in the landscape and absorbed by soil particles. Carbon isotopes (13C) can help distinguish the sources of eroded soil and place soil conservation strategies where most needed. Their reduced labour requirement gives them a strong advantage over conventional methods, such as erosion plots and pins. Nitrogen is one of the cornerstones of plant life. Nitrogen isotopes (15N) can help determine the most efficient way to apply nutrients through fertilisers, crop residues and animal manures, in order to avoid the production of GHGs such as nitrous oxide. 15N can also be used to quantify biological nitrogen fixation processes (BNF), through which nitrogen is absorbed from the air by plants and then left in the soil for the next crop.
Plant breeding. Modern nuclear breeding technology packages combine mutation induction and modern efficiencyenhancing biotechnologies, providing a means of following mutation events without being influenced by environmental fluctuations in the field, as is the case with standard phenotypic evaluations of plant traits. In addition, it is possible to identify mutation events in genes thought to be responsible for important crop traits such as drought tolerance or disease resistance, thanks to protocols combining mutation discovery technologies with the latest information on genome sequencing, such as Targeting Induced Local Lesions in Genomes (TILLING) for the identification of putative mutants, in vitro mutant selection for biotic and abiotic stresses, and micro-propagation of vegetatively propagated crops such as cassava, banana and yam.
Livestock support. Nuclear and nuclear-related immunoassays and molecular techniques support the joint efforts of veterinary authorities, extension services and farmers to control and eradicate diseases that impair productivity and trade in livestock and their products. These sensitive, specific and rapid techniques offer significant advantages over conventional methods, including the possibility of on-site use. Analytical tools such as ELISA, PCR, real time PCR and sequencing use isotopes to label protein and nucleic acid molecules and can be used for detection, monitoring, and characterization of harmful pathogens.
Methane production in ruminants is negatively correlated with energy utilization and can range from 2 to 12 percent of the gross energy intake. Radioisotopes, stable isotopes and 16S rDNA-based techniques can be used to evaluate and monitor the nutritive value of animal feeds and to enumerate and study rumen microbial diversity. Reducing enteric methanogenesis is beneficial from the standpoint of increasing energy efficiency of the animal and from an environmental perspective.
Reproductive performance and artificial insemination can be improved by monitoring various hormones, e.g. progesterone, LH, testosterone, oestradiol, T2, T3, leptines, and FSH. Also, the use of 32P, 35S allows the characterization and selection of desirable breeding traits.
