1. Title

Use of fallout radionuclide tracers for evaluating soil redistribution and nutrient dynamics in Zimbabwean farming systems

2. Research Officers

Chikwari E.

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3.  Problems and Objectives


  • To determine catchment-wide soil redistribution rates (erosion and sedimentation) and phosphorus losses and enrichment in different farmer settlements as influenced by variable farmer practices.
  • To evaluate intermittent soil and phosphorus losses in fields of variable soil conservation management practices and their effects on maize yields.
  • To evaluate nitrogen dynamics in varying conditions of limited and optimum soil conservation practices and its effect on maize yields.
  • To determine the effect of soil redistribution on soil organic carbon dynamics under different soil management scenarios. 


4. Justification

Answers to questions below can be provided by using isotopic and nuclear techniques:

  1. Where are those areas of critical land degradation?
  2. How much is the soil loss by erosion and where does the lost soil (and its nutrients) go?
  3. What is the impact of land use change on soil fertility (soil organic matter)?
  4. How can the soil be conserved in the most efficient way?

5. Details of each trial: Sites                                

 Site name                                          Design                          Plot size               

Communal, old medium and new resettlement areas used.

6. Treatments and Measurements

The  approach uses the fact that fallout is uniform in areas that received same rainfall during the fallout event

FRNs are quickly fixed on clay particles

FRNs activities analysed by gamma spectrometry

7. Bibliography

8. Publications