Valorization of the Natural Phosphate of Tilemsi (PNT) for the Development of the Agricultural Productions in Mali

Author(s): TRAORE Lamine, KONE Mama, BOUHSANE Mohammed, Richardson Jed, FRANCE Marie, Hosanee Jay

In Mali, the deficiency of agricultural soils in phosphorus is one of the limiting factors in crop production. They respond well to phosphorus fertilization, but the high price of imported chemical fertilizers limits their use by the producers. However, Mali has large deposits of natural phosphate in the Tilemsi Valley (PNT) in northern Mali. Faced with this situation, the Government encouraged the use of local fertilizing resources including the PNT. Despite the satisfactory results of several years of research and popularization, the PNT was poorly adopted by the producers because of its powdery appearance, which made it difficult to apply in the field, its low solubility in the soil, which made its effect noticeable on crops in the second year of its application and its brown color reminiscent of that of earth made the producers believe that it had no fertilizing value. Faced with these problems relating to the physical appearance and the low solubility of the PNT, the laboratory work of GREAT QUEST Fertilizer SA resulted in the development of simple formulations based on enriched granular PNT 27% P2O5 (average content) and 35% P2O5 (high content) for direct application and NPK complex formulations based on granulated enriched PNT 35% P2O5 mixed mainly with urea, potassium, and sometimes with other nutriments like sulfur and boron (NPK 15-15-15; NPKSB 14-18-18-6-2) with a solubility in citric acid of 71.1%. The results of four years of experimentation of enriched granular PNT in the research stations and in the peasant environment showed a greater or equal effect than the other popular fertilizers. This project aims to improve phosphate nutrition and crop production by using granulated formulations of enriched PNT 27% P2O5 and 35% P2O5.

Deficiency, Phosphorus, Phosphate Rock, New Formulations, Soil Fertility

1. Bagayoko M. & Coulibaly B.S. 1995. Promotion and evaluation of Tilemsi phosphate rock in Mali agriculture. In H. Gerner &A.U. Mokwunye, eds. Use of phosphate rock for sustainable agriculture in West Africa, pp.77 – 83. Miscellaneous Fertilizer studies N° 11 Muscle Shoals, USA, IFDC Africa.
2. Bationo A. Kaola S. Ayuk. E. 1998. Fertlity of soil for cereal production in the sahelo-soudanian zone and evaluation of natural phosphates. Cahiers Agricultures. 7 (5): 365-371.
3. Bationo A. Ayuk E. Ballo D. & Koné M. 1997. Agronomic and economic evaluation of Tilemsi phosphate rock in different agroecological zones of Mali. Nutrient Cycling Agrosyst. 48, 179-189.
4. Bationo, A., S.H. Chien, J. Henao, C.B. Christianson, and A.U. Mokwunye. 1990. Agronomic evaluation of two un acidulated and partially acidulated phosphate rocks indigenous to Niger. Soil Sci. Soc. Am. J. 54:1772-1777.
5. Boiffin J. Sebillotte M. 1977. Le phosphore et son emploi dans l'exploitation agricole. Institut National d'Agronomie Ed. Paris. (Thèse de Doctorat)
6. Budavari S. (1996). Merk Index. Whitehouse Station, NJ : Merk & Co.
7. Chien S.H. 1977. Thermodynamic considerations on the solubility of phosphate rocks. Soil Sci. 123: 117 - 121.
8. Doumbia M. D. Hoosner L.R. Onken A.B. 1993. Variable sorghum growth in acid soils of subhumid West Africa. Arid soil research and reabilitation. 7 (4): 335-346.
9. FAO. 2004. Use of phosphate rocks for sustainable agriculture. FAO fertilizer and plant nutrition Bulletin N° 13, 90 p.
10. Flash E. N. Quak W. Van D. A. 1987. A comparison of the rock phosphate-mobilizing capacities of various crop species. Trop. Agric. 64: 347 - 352.
11. Germida J. J. Jansen H. H. 1993. Factors affecting the oxidation of elemental sulfur in soils. Fer. Res. 35: 101-114.
12. GREAT QUEST Fertilizer Ltd. 2011. Mali rock phosphate economic study report.
13. Hammond L. L. Chien S. H. Mokwunye A. U. 1986. Agronomic value of unacidulated and partially acidulated phosphate rocks indigenous to the tropics. Adv. Agron. 40: 89-140.
14. Hedley M. J. Hussin A. Bolan N. S. 1990.. New approaches to phosphorus fertilisation. Phosphorus requirements for sustainable agriculture in Asia and Oceania. Proceedings of a symposium, 6-10 March 1989.: pp. 125 -142.
15. Hinsinger P. & Gilkes R.J. 1997. Dissolution of phosphate rock in the rhizosphere of five plant species grown in an acid, P-fixing substrate. Geoderma, 75: 231-249.
16. IFDC-IER. 1982. Rapport de la campagne : Maximisation de la rentabilité d’utilisation du phosphate tricalcique par les paysans. Doc. Com. Tech, BAMAKO, 12-16 Avril 1983
17. IFDC-IER. 1989. Phosphate fertilizers (IFDC/West Africa Project). Final Summary Report to IDRC.
18. IER-FED. 1986 : Effets comparés de différents composés granulés de phosphates naturels de Tilemsi sur les rendements du maïs, cotonnier, mil, sorgho, Riz. Rapport IER Bamako, 22p.
19. Jenny F. 1973. Expérimentation agronomique sur les phosphates naturels de Tilemsi (Mali) en conditions de culture sèche. Agronomie Tropicale. 28: 1070-1078.
20. Johri J. K. Surange S. Nautiyal C.S. 1999. Occurrence of salt, pH, and temperature-tolerant, phosphate solubilizing bacteria in alkaline soils. Current Microbiology. 39: 89 - 93.
21. Komy H. M. A. 2005. Co-immobilisation of Azospirillum lipoferum and Bacillus megaterium for successful Phosphorus and nitrogen Nutrition of Weat Plants. Food technol. Biotechnol. 43 (1) p. 19 - 27.
22. Lehr J.R. & McClellan G.H. 1972. A revised laboratory reactivity scale for evaluating phosphate rocks for direct application. Bulletin Y-43. Muscle Schoals, USA. Tennessce Valley authority. In FAO fertilizer and plant nutrition Bulletin N° 13: Use of phosphate rocks for sustainable agriculture 41 p.
23. LUXCONSULT S.A. 1985. Essais d’utilisation des phosphates naturels de Tilemsi. Étude de préfactibilité et essais d’accompagnement en vases de végétation. Projet FED, Luxembourg, 97p.
24. Morel R. 1996. Les sols cultivés. 2e édition Lavoisier, Paris.
25. Nahas E. 1996. Factors determining rock phosphate solubilization by microorganisms isolated from soil. World J. Microbiol. Biotechnol. 12, 567- 572.
26. Nautiyal C. S. 1999. An efficient microbiological growth medium for screening phosphate solubilizing microorganisms. FEMS Microbiol. Lett. 170: 265 - 270.
27. Piéri C. 1989. Fertilité des terres de savanes, bilan de 30 ans de recherche et de développement agricoles au sud du Sahara. Ministère de la coopération et IRAD-IRAT, 444p.
28. SAFGRAD (Semi-arid Food Grain Research And Development). 1985. Rapports annuels. Institut d’Economie Rurale (IER), Mali.
29. SAMAKE F. 1987. Contribution à la valorisation du phosphates naturels de Tilemsi (Mali) par l’action d’acides minéraux et de composés organiques humiliés. Thèse Docteur-Ingénieur INPL, Nancy, 198 p.
30. SANOGO Z., GABOREL C.H., TRAORE B. 1978. Etude des phosphates naturels de Tilemsi en zones cotonnière (synthèse des travaux de recherches). Rapport IER, Bamako, 63 p.
31. Tisdale S. L. Nelson W. L. Beaton J. D. 1985. Soil and fertilizer phosphorus. Dans soil fertility and fertilizers, 4e ed. Chapitre 8:189-248
32. Toro M. Azcon R. Barea J. M. 1998. The use of isotopic dilution techniques to evaluate the interactive effects of Rhizobium genotype, mycorrhizal fungi, phosphate solubilising rhizobacteria and rock phosphate on nitrogen and phosphorus acquisition by medicago sativa.
33. Biology and Fertility of Soils. 138: (2): 265-273.
34. Traoré L. 2010. Effet de l’utilisation de microorganismes dissolvant le phosphate naturel de Tilemsi sur la croissance et la production du maïs (thèse de Doctorat, Université de Bamako, 148 pages).
35. Traoré L. 2012. Accord de consultation IER/GREAT QUEST SA : Rapport de l’étude du marché des engrais phosphatés dans les pays de la sous- région de l’Afrique de l’Ouest : Mali, Burkina Faso, Niger et Sénégal.
36. Traoré L. 2014. Contacts personnels avec des responsables des services de vulgarisation, des organisations paysannes, des autorités politiques et administratives des différentes régions ayant abrité les essais agronomiques du projet Phosphate sur les contraintes de production agricoles au Mali.
37. Truong, B, Fayard, Ch. 1993. Etude de préfaisabilité pour une production d’engrais au Mali à partir des Phosphates de Tilemsi,
38. Perrott K. 2003. Direct application of phosphate rocks to pastoral soils -phosphate rock reactivity and the influence of soil and climatic factors. In S.S.S. Rajan & S.H. Chien, eds. Direct application of phosphate rock and related technology: latest developments and practical experiences. Proc. Int. Meeting, Kuala Lumpur, 16-20 July 2001. Muscle Shoals, USA, IFDC. 441 p.
39. Weil S. Gregg P.E.H. & Bolan N.S. 1994. Influence of soil moisture on the dissolution of relative phosphate rocks. In L.D. Currie and P. Loganathan, eds. The efficient use of fertilizers in a changing environment: reconciling productivity and sustainability, pp. 75 – 81. Occasional report N° 7. Palmerston North, New Zealand, Fertilizer and Lime Research Centre, Massey University.