Integrated Isotopic Approaches for an Area-wide Precision Conservation to Control the Impacts of Agricultural Practices on Land Degradation and Soil Erosion- D1.20.11


Objective:

The overall objective is to develop integrated isotopic approaches to identify hot spot or critical areas of land degradation in agricultural catchments for effective soil conservation measures (precision conservation).

Specific research objectives are (i) to develop the combined use of Fallout Radionuclide (FRN) techniques with conventional techniques and spatial analysis to establish soil redistribution patterns and rates over several temporal scales on an area-wide basis (catchment), (ii) to develop and validate protocols for the application of compound specific stable isotope (CSSI) techniques to identify and apportion the amount of source soils (land-degraded areas) from main land uses/management (cropland, grassland and forestland) in the catchment, (iii) to integrate nuclear based approaches with other non-nuclear techniques through modelling and other tools to establish comprehensive soil redistribution studies on an area-wide basis and (iv) to create the basis to develop decision support tools for implementing precision conservation and contributing to sustainable land management.

Activities:

Agricultural Practices on Land Degradation and Soil Erosion















This CRP, which was formulated on the basis of recommendation of a Consultants' Meeting held at IAEA Headquarters, Vienna, 5-7 November 2007, is in its third year. The first RCM of the CRP was successfully held at IAEA headquarters in Vienna from 8 to 12 June 2009. The second RCM of this CRP was held at the National Centre for Atomic Energy, and Nuclear Sciences and Applications (Centre national de l'énergie, des sciences et des techniques nucléaires (CNESTEN) in Rabat, Morocco, from 27 September to 1 October 2010. Eight research contract holders from Chile, China People's Republic, Morocco, Poland, Russian Federation, Syrian Arab Republic and Vietnam, four technical contract holders from Germany (University of Hohenheim), New Zealand (National Institute of Water & Atmospheric Research), United Kingdom (University of Exeter) and Belgium (University of Ghent) attended the meeting, and three agreement holders from Australia (CSIRO), Canada (University of Manitoba) and United Kingdom (University of Plymouth).

The third RCM was held at IAEA Headquarters in Vienna, in July 2012 at the time of the International Symposium on "Managing Soils for Food Security and Climate Change Adaptation and Mitigation". The purpose of the RCM was to review project progress of each participant. The final RCM was held in Vienna from 4–8 November 2013. The results obtained for the last five years were discussed. The participants also discussed their contribution to a TECDOC.

Key findings:

  • In order to establish spatial patterns of soil redistribution on an area-wide basis based on the use of FRN, appropriate extrapolation and up-scaling approaches must be developed. Several approaches have been explored and tested in this CRP. These include:
    - The use of representative units as a basis for extrapolation (e.g. Morocco, Canada ),
    - Spatial sampling programmes aimed at maximising the information return from a limited number of samples (transects, grids, random spatial sampling), as undertaken in Italy, Syria, China, Morocco, Chile and Canada,
    - Paired catchment approaches (e.g. Chile), and
    - Nested subcatchments (Poland).
    These tests represent encouraging first steps in the development of effective extrapolation and up-scaling procedures, but further work is required in the coming years of the CRP, particularly in terms of their coupling with appropriate spatial analysis techniques.
  • CSSIs were shown to be a useful technique to identify & apportion hot spots of land degradation/erosion (by linking biomarkers of land use to the sediment in deposition zones).
  • The first draft of a harmonized protocol for the application of CSSI techniques to identify critical areas of land degradation at the catchment scale in a range of environments and land use systems was developed. This protocol has been sent to the CRP participants in October 2010 for further validation under different agroecological conditions.
  • The link of FRNs (Cs-137, Be-7 and Pb-210) with CSSIs (e.g. fatty acids) also improved the power for distinguishing the sediment sources (like in Australia).
  • Integrating the use of FRNs such as Pb-210 and CSSIs showed how land use history over the last hundred years can be reconstructed. The CSSIs of different depth layers in a sediment core can identify land use changes associated with changes in sediment accumulation rates (defined by Pb-210). Historical documents could help confirm the findings (e.g. New Zealand).
  • The protocol for the application of CSSI techniques to identify critical areas of land degradation at the catchment scale is being validated under different agroecological conditions and land use systems (i.e. Chile, China, Morocco, Poland, the Russian Federation, Syrian Arab Republic and Vietnam).

Participants:

[Download pdf]

Reports:

  • Report of the consultants' meeting, IAEA Headquarters 2009, Vienna, Austria. [Download pdf]
  • Report of the First RCM, 8 - 12 June 2009, Vienna, Austria. [Download pdf]

Project Officer:

Gerd Dercon