Seeding density, persistence and contribution to biomass of two forage legumes Aeschynomene histrix Poir. and Stylosanthes hamata (L.) Taub. in a natural pasture.

Résumé

This study aimed to investigate the possibilities to enrich natural pastures in the Sudanian zone of Burkina Faso by introducing two forage legumes, Aeschynomene histrix and Stylosanthes hamata. To do this, a randomized complete block design with 6 replications and 10 treatments was installed. The treatments were: natural pasture without legume introduction; natural pasture sown with one of the two legumes or without; two seeding densities of the two legumes (400 feet and 800 feet of legumes/m²); two levels of phosphate fertilization (100 kg P₂O₅/ha/yr and 0 kg P₂O₅/ha/yr). Results showed that legumes were established with high seedling densities (329-595 plants/m²). The legumes introduced into the pasture had a variable specific contribution between 15 and 30%. A. histrix contributed about 1.1 t DM/ha and 2.9 t DM/ha for the treatments without and with phosphorus application, respectively. P₂O₅ application particularly increased biomass production in the recipient plots by about 25%, and A. histrix biomass production by about 50%. Phosphorus fertilization improved the biomass contribution of the two legumes where S. hamata gave the best results with 49% and 48% of the biomass without phosphorus input respectively for the two seeding rates.