Fodder-quality improvement through contour planting of legume-shrub/grass mixtures in croplands of Rwanda highlands

Abstract

The leguminous woody shrub species Sesbania sesban and Calliandra calothyrsus were planted with the grasses Pennisetum purpureum and Setaria splendida on contour lines in association with wheat and beans in order to improve the grass based fodder system in the Buberuka highlands of Rwanda. Setaria, calliandra and sesbania showed a higher productivity when shrub and grass species were mixed than in the sole stand. The crude protein yield of all grass-shrub mixtures was higher than in grasses alone and the crude protein of the grasses was increased when combined with a leguminous shrub. Calliandra with Setaria gave the highest fodder quality and showed the lowest competition with crops. An optimal system for satisfying dry matter and protein requirements of local and improved cattle was estimated by linear programming. Shortest length of fodder planting is obtained by the pennisetum based system in sole stand and in combination with calliandra. The crop loss was the least when Setaria was grown alone or in combination with calliandra. From production, nutrition and economic considerations it appears that leguminous shrubs have a role in improving fodder production in the Rwandan highlands.