Effect of chemical properties of soils on gum elementary compositions from Acacia senegal var. kerensis in Samburu and Marsabit Districts

Joseph K. Lelon*, Meshack O. Muga, David W. Odee, Chemuku Wekesa and Beatrice Ndakwe

Kenya Forestry Research Institute, P. O. Box 20412, Nairobi, Kenya.

E-mail: jklelon@yahoo.com.

Accepted 24 December, 2009

   Abstract

Geographical Positioning System was used to mark the sites of Acacia senegal var. kerensis in Marsabit and Samburu districts. Soil and gum samples were collected for analysis of pH, carbon, nitrogen and phosphorus. Soil pH (6.0 - 6.7) varied significantly (p < 0.05) with pH of gum (4.54, 4.50, 4.51 and 4.52) in all the sites. In Merrile, organic carbon in gum (0.15%) was significantly higher than 0.073, 0.055 and 0.027% in Logologo, Laisamis and Sereolipi, respectively. Soil nitrogen (0.30, 0.4 and 0.8%) in Merrile, Laisamis and Logologo were significantly correlated (p < 0.05) to the nitrogen (0.31 - 0.32%) in gum, while soil N (0.3%) in Sereolipi was not significantly correlated with gum nitrogen (0.23%) and was significantly lower than those of Merrile, Laisamis and Logologo (0. 31, 0.32 and 0.32%). Phosphorus (700.2 and 705.2 ppm) in gums from Sereolipi and Merrile were significantly higher than 412.2 and 412.2 ppm in Laisamis and Logologo. pH (4.5 - 4.54) and nitrogen content (0.31 - 0.32%) in gum from Merrile, Laisamis and Logologo were within the international standards (pH 4.2 - 4.8) and (0.24 - 0.41%). Chemical properties of soils were major factors that influenced the gum quality.

Key words: Acacia senegal, soil, gum arabic quality, sites.