Teneurs en oligo-éléments cuivre (Cu), fer (Fe), manganèse (Mn) et zinc (Zn), et rapport fer-manganèse (Fe : Mn) des pâturages naturels de la Sous-Région de l'Ituri (République du Zaïre)

Abstract

Copper (Cu). Iron (Fe), Manganese (Mn) and Zinc (Zn) and Iran to Manganese ratio (Fe/Mn) in natural pastures of Ituri region (Republic of Zaire). The concentrations of Copper, Iron, Manganese and Zinc, and the Iron to Manganese ratios were determined in 91 samples of pasture grasses from different parts of Ituri area, in Zaire. The samples were divided into 3 groups or sectors according to their geographic origin (southern, middle and northern), and refer to 20 different species of graminaceae. Analytical results showed normal levels of Copper. Iron and Manganese (Overall mean values of 12.33 ppm DM, 103.75 ppm DM and 81.75 ppm DM respectively). The levels of Zinc were generally very low and the mean value in the whole material was 36.40 ppm DM. The general mean value of the Iron to Manganese ratio of 1.68 was satisfactory in spite of slightly low values in the middle (1.36) and the north (1.25).