Nuclear Techniques for a Better Understanding of the Impact of Climate Change on Soil Erosion in Upland Agro-Ecosystems - D1.50.17


Background:

The report of 2014 from the Intergovernmental Panel on Climate Change (IPCC) emphasizes the expected impact of climate change, especially in upland areas. The effects of climate change are expected to worsen, bringing more extreme weather events such as droughts, floods, heat waves, and unpredictable rainfall distribution, all of which threaten food security and could make agricultural production in uplands difficult, if not impossible.

Nuclear Techniques for a Better Understanding of the Impact of Climate Change on Soil Erosion in Upland Agro-ecosystems Climate change effects are highly visible in upland areas also designated as "less favoured areas" due to their challenging physical conditions (terrain, topography and climate) and farmers’ high vulnerability and exposure to climate change as compared to lowland farming communities. The document Agenda 21 of the United Nations (UNCED) emphasized that in the 21st century, the focus of agricultural development will have to shift from developing green revolution technologies for lowland areas, to finding ways of improving the productivity of agriculture in marginal areas.

Upland agro-ecosystems will face three major challenges related to food security and climate change in the coming decades: (1) increasing food production while improving, protecting and optimizing soil and water use efficiency, (2) adapting to climate change impacts on soil and water resources, and (3) contributing to climate change mitigation. Adapting to climate change in the uplands requires agricultural soil and water management practices that make agricultural production systems resilient to drought, floods and land degradation, to enhance the conservation of the natural resource base for sustainable upland farming.

Integrated isotopic approaches can help develop strategies for targeted and effective soil management practices to control soil degradation in upland agroecosystems.

Objective:

This CRP aims to (i) develop combinations of nuclear techniques to assess impacts of changes on soil erosion, and (ii) distinguish and apportion impacts of climate variability and agricultural management on soil erosion in upland agro-ecosystems.

Nuclear techniques including Fallout Radionuclides (FRNs) such as caesium-137 (137Cs), lead-210 (210Pb), beryllium-7 (7Be) and plutonium-239 and 240 (239+240Pu), Compound-Specific Stable Isotope (CSSI) techniques based on the measurement of carbon-13 (13C) natural abundance signatures of specific organic compounds (i.e. fatty acid) and Cosmic Ray Soil Moisture Neutron Probe (CRNP) will be used to fulfil the CRP objectives.

Participants:

Twelve countries participate in this CRP: four research contract holders from China, Iran - Islamic Republic of, Madagascar and Morocco, seven agreement holders from Canada, Italy, United Kingdom, United States of America, Spain and Switzerland, and two technical contractors from Austria and New Zealand.

Activities:

This CRP was formulated on the basis of the recommendations of a consultants’ meeting held at IAEA headquarters, Vienna on 8-12 December 2014. The First Research Coordination Meeting was held on 25-29 July 2016 in Vienna, Austria) and the Second RCM took place at the Centre National de l’Energie, des Sciences et des Techniques Nucléaires (CNESTEN) in Rabat, Morocco, from 16 to 20 April 2018. The IAEA mid-term review of the CRP that took place on 13 March 2019 praised the results reached so far and the Third RCM was held in Vienna, Austria from 14 to 17 October 2019. Currently, the CRP is focusing to test the 137Cs resampling approach which appears to be one of the most suitable techniques for monitoring the temporal evolution of soil erosion processes. The Fourth and final RCM will take place in Vienna, Austria from 5 to 9 July 2021.

Key results:

Since the start of CRP, the FRN and CSSI techniques have been developed or refined to deepen our understanding of erosion processes affecting upland agro-ecosystems. A new and unique FRN conversion model MODERN was developed, the use of CRNS for soil moisture monitoring of upland agroecosystems was tested and validated and plutonium isotopes (239+240Pu) were tested as new soil erosion tracer versus other more mature FRN techniques under various agro-environments in Switzerland, South Korea and Austria.

To date, key activities carried out within this CRP have led to these publications: (a) open-access handbook on using cosmogenic 7Be to evaluate recent soil erosion magnitudes and short-term erosion dynamics; (b) FAO handbook on use of 137Cs for soil erosion assessment, (c) two IAEA TECDOCs: first reporting about soil moisture mapping with portable cosmic ray neutron sensor (IAEA-TECDOC-1845) and second providing guidance for sediment tracing using CSSI technique based on the measurement of δ13C signatures of fatty acids (IAEA-TECDOC-1881) (d) 19 peer-reviewed papers in international scientific journals and (e) 20 other publications and presentations at scientific events.

Project Officer:

Lee Heng