EGU22-4891, updated on 27 Mar 2022
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Nutrient inputs to sahelian soil by atmospheric dust deposition 

Rizewana Marecar1, Beatrice Marticorena1, Gilles Bergametti1, Corinne Galy-Lacaux2, Rémi Losno3, Jean Louis Rajot1,4, Servanne Chevaillier1, Anais Feron1, Sylvain Triquet1, and Maria Dias-Alves2
Rizewana Marecar et al.
  • 2LAERO, CNRS, UPS, IRD, Toulouse, France
  • 3IPGP, Paris, France
  • 4iEES Paris, UMR IRD 242, UPEC, Sorbonne Université, CNRS, INRA, Bondy, France

Dust emission affects soil fertility through nutrient loss in source regions while dust deposition can represent a significant nutrient input for remote ecosystems. If the Sahel is a well-known dust source region, it is also a region where large amounts of dust from the Sahara desert are deposited.                                                         

To quantify the input of nutrients that mineral dust deposition represents for Sahelian soils and to identify the sources responsible for these deposits, a dedicated instrumental setup was deployed during two years in two Sahelian sites of the INDAAF Network : Bambey (Senegal) and Banizoumbou (Niger). The insoluble and the soluble fraction of the atmospheric deposits have been collected separately and analysed. In parallel,  the elemental composition and carbon content of PM10 were determined. A special attention was given to the most important nutrients for the soil fertility in this region (P and N) and on the organic C. Other elements (Fe, Al, K, Ca, ...) were also analysed in order to identify the sources of the deposited particles.                                                

For most of the analysed elements, the elemental compositions of PM10 and dust deposit are consistent and the dust samples composition reveals a seasonal change. During the dry season, the dust composition is similar in Niger and Senegal. During the wet season, mineral dust in Niger exhibits a typical signature of sahelian soils (i.e., enriched in Fe and depleted in Ca) while in Senegal dust composition suggests a regional source enriched in Ca. The analysis of the soluble and insoluble fraction of dust deposition allows to estimate the total annual amount of P, N and C deposited on Sahelian soil.

How to cite: Marecar, R., Marticorena, B., Bergametti, G., Galy-Lacaux, C., Losno, R., Rajot, J. L., Chevaillier, S., Feron, A., Triquet, S., and Dias-Alves, M.: Nutrient inputs to sahelian soil by atmospheric dust deposition , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4891,, 2022.


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