Abstract
A pot experiment was conducted to assess the effect of mineral fertilization and compost on the growth and chemical composition of ryegrass (Lolium perenne L.) grown on two Malian agricultural soils coming from Baguinéda, abbreviated as Bgda, (12°23′ S, 7°45′ W) and Gao (16°18′ N, 0°). Treatments included non‐fertilized control, NPK alone, NPK + C25, NPK + C50, NPK + C100, PK + C50, NK + C50, NP + C50, K + C50, P + C50, N + C50, and C50 alone, where NPK represents the non modified Hoagland's solution and C25, C50, and C100 represent the different rates (25, 50, and 100 T/ha) of compost. Compost and mineral fertilization significantly increased dry matter production. The application of 50 T/ha of compost alone increased the dry matter yield by 10 and 17.5% while mineral nitrogen–phosphorus–potassium (NPK) increased yield by 69.7 and 65% for Gao and Bgda, respectively. The combination of compost and mineral NPK (NPK + C25 for Gao and NPK + C50 for Bgda) affected the highest dry matter yield. For both soils, N concentrations in plants increased significantly with compost rate. Phosphorus and K concentrations in plants varied according to the soil. The application of compost increased the uptake of iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), and potassium (K from both soils). Increases in soil organic carbon, available P, calcium (Ca), magnesium (Mg), Fe, Mn, Zn, Cu, K, and pH were observed in treatments receiving compost. Therefore, compost appeared to be a good supplier of nutrients for tropical soils.
Acknowledgments
The authors gratefully thank Mr. Bouno Kampo engineer in Baguinéda, Mr. Diallo Yacouba, soil scientist in BICD (Bureau d'Ingénieurs Conseils pour le Développement, in Bamako), Mr. Seydou Traoré (1er adjoint au commandant de cercle de Gao) and Mr. Boncana Touré (chef SSA de la Direction Régionale de l'Agriculture de Gao) for their assistance in sample collection and transportation. The financial support of this study was provided by the Belgian Technical Cooperation.