The objective of the study was to evaluate the influence of Tithonia diversifolia in association with three hilling moments in order to identify the best moment (s) associated with Tithonia diversifolia improve soil fertility and thus give bean plants the ability to withstand the attack of bean flies and thus hope to have good yield of common beans. The experimental design was the split plot with three repetitions, with beans’ variety called Kirundo as the main plots. They were subdivided into two subplots, one of which corresponded to the application of Tithonia diversifolia and the other without Tithonia diversifolia. The main plots were nine in total and constituted six different treatments evaluated. A single fresh biomass dose of Tithonia diversifolia equivalent to 10 tons per hectare was applied in all plots with Tithonia d. two weeks before sowing beans. There were significant differences between treatments. Bean’ yield increased by an average of 212.28%, the weight of 100 seeds was improved by an average of 7.2%, the number of pupae such as the cumulative number of dead bean plants was significantly reduced by application of Tithonia diversifolia in this highly endemic study environment for bean maggot, the vigor of bean plants has been improved, there has been no interaction between Tithonia diversifolia and ridging at any given time. In conclusion, the application of Tithonia diversifolia increased bean yield in soil with many soil fertility constraints and highly endemic for bean maggot (Ophiomya spp).

The constraints threatening plantain production in the eastern of DR-Congo include soil fertility. An experiment was conducted at the National Institute for Agricultural Study and Research at Nioka Research Station to evaluate the effect of organic manures and mulch on growth and yield parameters of plantain (Musa AAB). This study revealed that response of organic manures was significant for all the parameters. Manure application enhanced significantly banana plant growth and yield. The highest bunches weight and yield were produced by the plants receiving manure (24.03t/ha) and mulch (23.24 t/ha) while, lowest bunches and yield were harvested in control plot without fertilizer (17.64 t/ha).

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.

The objective of this study was to evaluate five species of green manure as improved fallow on cassava yield. The trial design was a complete randomized block with three repetitions. The treatments consisted of different species of green manure and one control. Two cassava varieties Mayombe and Sawasawa were used. The yield was significantly enhanced by Tithonia diversifolia up to 343.02% for Mayombe variety compared to the control, ie 44.17 t/ha against 9.97 t/ha for the control. Also, the yield of Sawasawa variety, was high in the order of 390.4%, i.e. 38.4 t/ha against 7.83 t/ha for the control with no fertilizer. In addition, Lab lab species enhanced also the yield to 309.2% or 40.80 t/ha for the Mayombe variety against 9.97 t/ha for the control, as for Sawasawa variety, the yield was improved by 119.6% or 17.2 t/ha against 7.83 t/ha for the control. Other species, including Mucuna preta, Crotalaria grahamiana and Crotalaria ochroleuca, improved yield of the Mayombe variety in the order of 137.7%, 129.3% and 62.7%, respectively. For Sawasawa variety, only Crotalaria grahamiana improved its yield by 106.5% compared to the control.

Better managements of soil fertility are imperative for rehabilitating degraded soil in order to increase crop yields. Our objective was to assess the effect of improved fallow of different combinations of herbaceous-shrubs species and microdose of fertilizer on maize-bean yield, aboveground organic carbon sequestration and soil proprieties improvement. The treatments consisted of Pennisetum purpureum, Setaria sphacelata and Tripsacum laxum or Tithonia diversifolia combinations with 3 shrub species (Leucaena diversifolia, Calliandra calothyrsus, and Albizzia chinens) and microdoses of fertilizer (NPK-manure), two controls treatments without fertilizer were also included. These treatments were arranged in a split-plot design with, the main plot treatment consisting of herbaceous-shrubs fallow type subdivided into four subplots of beans ([M211], [NAMULENGA] [CURANTINO] and [VCB] cropped with three maize varieties [SamVita A and B], and [Gv664]. Application of microdose and herbaceous species combination increased bean and maize grain yield at both sites 21 months after trial initiation. No significant difference was observed between the different combinations in both sites and for the 3 planting seasons for assessed parameters. Herbaceous combinations increased significantly the number of nodules (P < 0.01). Highest biomass yield, C sequestration number and biomass of earthworm were found in the herbaceous-shrubs combinations treatments and lower in NPK-manure and control treatments in both sites. In addition, the number of earthworms was enhanced with application of microdose of fertilizers (546) and herbaceous-fallow grassland (725) compared to control (282) 2 years after trial initiation at Mulungu site. No significant difference was observed between the different combinations in both sites for soil temperature and moisture variation.