Fallow is one of the methods used to restore soils fertility and to produce fodder for domestic animals. The objective of this study was to compare the biomass yields of different species of shrubs and grasses in contrasting soils in South Kivu Province in the Eastern of Democratic Republic of Congo. The experimental design was a randomized block containing four repetitions. Each repetition contained four plots corresponding to four species of gramineas (Pennisetum purpureum, Setaria sphacelata, Brachiaria ruziziensis and Tripsacum laxnum) or shrubs (Albizzia chinensis, Leucaena diversifolia, Calliandra calothyrsus and Leucaena leucocephala). Highly significant differences (P = 0.001) were observed between species and between sites for all observed parameters. The quantities of biomass produced by the Pennisetum in the two sites (29.31 t/ha) were significantly higher than those produced by the 3 others species followed by Setaria (19.54 t/ha), Brachiaria (13.84 t/ha) and Tripsacum (13.8 t/ha). The same trend was observed for shrubs species, the quantities of biomass produced by the Calliandra in the two sites (11 t/ha) were significantly higher (P = 0.001) than those produced by the 3 others species followed by Leucaena diversifolia (8 t/ha), Leucaena leucocephala (3 t/ha) and Albizia chinensis (2 t/ha). Concerning the sites, a highest significant difference was observed between the two sites, the biomass yields produced at Mulungu (7.3 and 23.7 t/ha) were significantly higher than those for Mushinga (4.7 and 14.5 t/ha), for shrubs and gramineas respectively. For forage biomass production and soil productivity restoration, the combination of Calliandra and Leucaena diversifolia, and pennisetum-setaria can be used as improved fallow in the conditions of the trial sites. There is a need for follow-up research on soil production restoration to include these four species in trial at both sites in South Kivu Province.