|Fig. 1: This is a picture of a barley field, which has benefited from the use of fertilizer (Source: Wikimedia Commons)|
It is well known how nuclear technology has played a major role in revolutionizing weapon capabilities and energy. What is not as well known, is the huge improvements that have been made in the agriculture industry due to utilizing the power of radioisotopes. In 1964, the Food and Agriculture Organization of the UN (FAO) and International Atomic Energy Agency (IAEA) set up a Joint Division of Atomic Energy in Food and Agriculture.  The purpose of this joint division was to coordinate research projects regarding the use of isotopes and radiation in fields of plant breeding, soil fertility, irrigation and crop proliferation, chemical resides in foods.  This paper will explore how radiation is used to enhance plant nutrition from fertilizers and to create seed variety mutations, both of which have created more efficiencies within the industry.
Fertilizer is used in agriculture in order to increase the soils fertility, and therefore increase crop production. Fig. 1 shows a picture of a barley field, which has likely created such high crop yield due to the use of fertilizer. For many countries, use of fertilizer is very costly, and incorrect use can lead to wasted money/resources and may damage the environment.  Radioisotopes are very useful in estimating the amount of phosphorous and nitrogen available in the soil, which helps determine the amount of phosphate and nitrogen fertilizers that should be applied to the soil.  Fertilizers labelled with radioactive isotopes which as P-32 and N-15 have been used in this process to determine how much fertilizer is taken and lost to the environment by the plant.  The goal is to achieve higher grain yields by optimizing the amount of uptake from the fertilizers.
Radioactive isotopes can also be used to study the characteristics in the soil to monitor uptake and use of essential nutrients by plants from the soil.  By using the radioactive isotopes as a tag, scientists can measure the exact nutrient and water requirements of a crop in particular conditions.  This is especially useful in areas when resources and water are scarce, such as in times of a drought.
Another major impact of radiation in agriculture is the utilizing radiation for to induce genetic alterations in order to improve crop variates and mutation breeding.  Using radiation-induced genetic alterations have become established as part of plant breeding methods. By applying doses of gamma or neutron irradiation, it is possible to create mutation to create crop varieties that are more disease resistant, tolerant to harsh conditions, show increased yield and have shorter growing times.  Around 1800 varieties of crop plants have been developed by using radiation induced mutation, which have been economically important.  One successful example of this was in Hungary, where they were trying to develop a new rice variety resistant to blast, a damaging rice disease.  They first attempted testing a French variety of rice, but due to differing climates between Hungary and France, the French rice would mature too late in Hungary and would not produce optimal crop yields. Thousands of these French seeds were irradiated with different amounts of gamma radiation to attempt to create earlier maturation. One variety headed three weeks earlier than the non-radiated mother seed, and so this seed was chosen to be propagated in Hungary. It was released in 1976 for commercial use under the name Nucleoryza. 
Radioactive isotopes can be applied in a number of ways to solve many problems in the agriculture industry and allow the industry to be more efficient. These applications are especially important for developing nations or areas where resources are scarce (such as California when water is limited due to a drought) and for preserving natural resources while meeting the challenges of food security.
© Maeve White. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 C. G. Lamm, Isotope and Radiation Applications to Agricultural Development in Asia and the Pacific Region," International Atomic Energy Agency, 8 Jun 81.
 B. Singh, J. Singh and A. Kaur, "Applications of Radioisotopes in Agriculture," Int. J. Biotechnol. Bioeng. Res. 4, 167 (2013).
 A. M. Bagher et al., "Nuclear Techniques in Agriculture and Genetics," Am. J. Biosci. 2, 102 (2014).