Greenhouse gas reduction

Agriculture produces a substantial amount of greenhouse gas emissions, which contribute greatly to global warming and climate change. Stable and radioisotopes can be used to develop technology packages that assist Member States to sustainably reduce these emissions, improve resource use efficiency and increase crop and animal productivity.

Agriculture is both a victim of and a contributor to climate change. On the one hand, agricultural activities contribute approximately 30 per cent of total greenhouse gas emissions, mainly due to the use of chemical fertilizers, pesticides and animal wastes. This rate is bound to further rise as a result of an increase in the demand for food by a growing global population, the stronger demand for dairy and meat products, and the intensification of agricultural practices.

On the other hand, these greenhouses gases include nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4), which all contribute to climate change and global warming and thereby have a profound impact on the sustainability of agricultural production systems. This does not yet take into account the greenhouse gas emissions associated with the use of pesticide, the environmental cost of which is largely unrecognized.

Together with the FAO, the IAEA aims to optimise and strengthen the capacities of Member States in using nuclear and isotopic techniques so they can develop technology to reduce greenhouse gas emissions and support the intensification of crop production and the preservation of natural resources.

Measuring greenhouse gas emissions using nuclear techniques

To reduce the emission of nitrous oxide, a greenhouse gas with a global warming potential 300 times larger than that of carbon dioxide, chemical fertilizers, pesticides and manure must be used conscientiously. Additionally, low-cost inhibitors that regulate nitrogen processes in soils should be implemented. All this requires detailed knowledge of the sources of greenhouse gas production through the various microbial processes in soil.

Nuclear techniques offer substantial advantages over conventional techniques for measuring the impact of climate change. Using the nitrogen-15 isotopic technique, scientists can identify the source of nitrous oxide production, which is important to find ways to reduce the emission of the gas.

The carbon-13 stable isotope technique, using the natural abundance of carbon-13 in the environment, allows researchers to evaluate soil quality and sources of carbon sequestered in the soil. This helps identify how various combinations of crop rotation, tillage and ground cover can enhance productivity and improve the efficiency with which increasingly scarce resources, such as water and chemical nutrients, are used.

Carbon sequestration – the capture and long-term storage of atmospheric carbon dioxide (CO2) in soil – currently presents the best solution to counterbalance the increase of greenhouse gases. This includes enhancing biomass production; the application of low-cost plant growth regulators and bio-fertilizers; agricultural conservation practices (no till, application of manure and biochar); nitrogen fixation by leguminous crops; reduced pesticide use; crop rotation; and mixed crop-livestock production. In addition, optimised animal feeding practices and manure management can reduce energy leakage and emissions.

To improve animal productivity and protect the environment from overgrazing, nuclear and related techniques can help formulate feed supplementation strategies. One way is to identify the combination of long chain hydrocarbon and natural carbon-13 on plants eaten by ruminants and in their faeces, which helps estimate their intake under grazing or grassland browsing conditions.