Scientific Research and Essays

  • Abbreviation: Sci. Res. Essays
  • Language: English
  • ISSN: 1992-2248
  • DOI: 10.5897/SRE
  • Start Year: 2006
  • Published Articles: 2754

Full Length Research Paper

Estimating soil available nitrogen with a hot H2O2/KCl extraction

T. B. Tié1, L. N. Diby1, 2*, E. Seyo2 and A. Assa3
1Department of Water, Forest and Environment, National Institute of Technology FHB, Yamoussoukro, Côte d’Ivoire. 2Swiss Center for Scientific Research (CSRS), Abidjan, Côte d’Ivoire. 3Department of Earth Sciences and Mine Resources, University of Cocody, Abidjan, Côte d’Ivoire.
Email: [email protected]

  •  Accepted: 21 May 2010
  •  Published: 30 September 2013


Appropriate and simple analysis methods for an accurate estimation of soil N mineralization potential are required to optimize N fertilizer recommendations. We used soils from non-cultivated and cultivated plots in central Côte d’Ivoire to investigate the quantum of ammonium (NH4+) that could potentially be mineralized. The soil was first treated with H2Oat 60°C for 2, 4, 6 or 8 h (and referred to as hot extraction) or at room temperature (25°C and referred to as 0 h). The NH4+-N extracted increased with the heating time but decline slightly after 6 h. More NH4+-N was extracted in non-cultivated plots with the hot extraction, and the difference was significant at 6 h. The NH4+-N measured with the hot extraction correlated significantly with the CEC. We obtained the strongest correlation in non-cultivated plots (r= 0.88, p < 0.0001) at 6 h, and the weakest also at 6 h but in cultivated plots (r= 0.64, p < 0.0001). Similarly, we observed a significant correlation between the NH4+-N extracted and the amount of N taken up by rice seedlings grown in pots, and the best correlation was again at 6 h. The study illustrated that N mineralization with H2Oat 60°C for 6 h is an appropriate procedure for extracting potentially mineralizable NH4+-N in soils.


Key words: Cation exchange capacity (CEC), extractable ammonium, ferralsol, N mineralization, total N.