Journal of
Soil Science and Environmental Management

  • Abbreviation: J. Soil Sci. Environ. Manage.
  • Language: English
  • ISSN: 2141-2391
  • DOI: 10.5897/JSSEM
  • Start Year: 2010
  • Published Articles: 287

Full Length Research Paper

The importance of proton supply in phosphate rock dissolution: Comparative study of three phosphate rocks from sub-Saharan Africa

Jeremias Gasper Mowo
  • Jeremias Gasper Mowo
  • World Agroforestry Centre, P. O. Box 30677 - 00100 Nairobi, Kenya.
  • Google Scholar
Bert Janssen
  • Bert Janssen
  • Wageningen University, P. O. Box 8005, 6700EC, Wageningen, Netherlands
  • Google Scholar
Oene Oenema
  • Oene Oenema
  • Wageningen University, P. O. Box 8005, 6700EC, Wageningen, Netherlands.
  • Google Scholar
Kenneth Masuki
  • Kenneth Masuki
  • World Agroforestry Centre, P. O. Box 26416 Kampala, Uganda
  • Google Scholar
Jerome Mrema
  • Jerome Mrema
  • Sokoine University of Agriculture, P. O. Box 3008 Morogoro, Tanzania.
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  •  Received: 09 April 2012
  •  Accepted: 13 June 2014
  •  Published: 31 July 2014

Abstract

The dissolution in hydrochloric acid of three phosphate rocks (PRs) from sub-Saharan Africa was studied in the laboratory and their agronomic effectiveness compared using soils from Tanzania, Ivory Coast, Kenya and Netherlands. The objective was to investigate the potential of the PRs in supplying phosphorus under conditions of limited and unlimited supply of protons (H+). The test crop was maize (Zea mais var. LG11). Results show that calcium carbonate content is an important factor determining differences between the PRs with respect to their effectiveness. They also show that (i) differences in the dissolution of the PRs manifested more at low than at high acid concentration, (ii) availability of enough protons is an important factor in PR dissolution, (iii) low rates of PRs should be more desirable than high rates and (iv) soil and plant factors have an important role in the effectiveness of a PR.

 

Key words: Phosphate rocks (PRs) effectiveness, extractable phosphorus, hydrogen ions concentration, calcium carbonate content, sub-Saharan Africa.