Evaluation of the Mineral and Nitrogen Contents of Three Forage Crops (Vigna unguiculata (L.) Walp., Pennisetum purpureum Schum. and Hyparrhenia diplandra (Hack.) Stapf.) Grown in the Boundji area (Republic of Congo)

Abstract

Pennisetum purpureum Schum., Vigna unguiculata (L.) Walp. and Hyparrhenia diplandra (Hack.) Stapf are fodder plants that can provide quality herbaceous above-ground phytomass for domestic animal feeding. They are used in degraded pasture restoration practices. The objective of this study was to evaluate the mineral elements and nitrogenous matter of these three forage crops. The latter were planted in the pedoclimatic conditions of the Boundji area. Phytomass samples were taken two months after planting by sowing seeds for Vigna unguiculata (L.) Walp., by cuttings for Pennisetum purpureum Schum. and by splitting the stumps for Hyparrhenia diplandra (Hack.) Stapf. The samples were oven-dried at 70 °C to constant weight and chemically analysed. The results obtained show that the mineral elements and nitrogenous matter vary from one forage species to another. Vigna unguiculata (L.) Walp. is the richest forage species in total nitrogenous matter (16.43 ± 2.43%) and digestible nitrogenous matter (117.50 ± 22.64 g/k DM). It provides excellent quality fodder capable of meeting the needs of maintenance, growth, reproduction, gestation and milk production in cattle. Pennisetum purpureum Schum. is the richest grass in total nitrogenous matter (8.43 ± 1.81%) and digestible nitrogenous matter (43.18 ± 16.83 g/kg DM). Pennisetum purpureum Schum. and Hyparrhenia diplandra (Hack.) Stapf produce good quality fodder to meet the vital needs of cattle. These results could be used for the improvement of degraded pastures in order to sustainably manage the pastoral ecosystem.