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Most soils in the Lubumbashi region are acidic (pH 4 to 6) and poor in available phosphorus. The production of crops such as common beans requires large amounts of chemical fertilizers, generally up to 200 kg ha−1of NPK10-20-10 compound fertilizer, recommended for good production, but which are not affordable for most of smallholder farmers. More over the pH range is not optimal for fertilizer efficiency. Under this circumstances fertilizers use efficiency can be made effective by arbuscular mycorrhizae (AMF) even when applied at low doses. In this study, four types of AMF inoculum (Acaulospora, Gigaspora, Glomusand Acaulospora-Gigaspora-Glomus) and an uninoculated control were selected and combined with two levels of NPK10-20-10 application, by bringing a quantity of products of 100 kg ha−1, 200 kg ha−1and unfertilized plot as control. Application of NPK 200 kg ha−1reduced colonization frequency and AMF spore density with 28.5 to 41.8%, respectively. Plants that received 200 kg NPK ha−1associated to Acaulospora-Gigaspora-Glomuswere less sensitive to bean fly than others. Application of 200 kg NPK ha−1as well as inoculation with Acaulospora-Gigaspora-Glomusor association of mycorrhiza with NPK fertilizers offered the similar number of pods per plant (8 to 10). Treatment with low doses of NPK (100 Kg NPK ha−1) combined with Acaulospora-Gigaspora-Glomusinoculum yielded well (15%) compared to the control and reduces the quantity of chemical fertilizers to be applied. NPK alone or inoculation with Acaulospora-Gigaspora-GlomusAMF inoculum improved bean yield by 12%.

Soil fertility in the Lubumbashi region often proves to be limiting factor for crop production due to their low nutrient reserves. The objective of this work was to evaluate the impact of arbuscular mycorrhizae on phosphorus uptake by maize on Ferralsol. The trial was conducted in pots with 30 kg or 60 kg of P2O5ha−1and a control. These three levels of phosphorus were combined or not with arbuscular mycorrhizae. The combinations of 30 kg or 60 kg of phosphorus with the inoculum led to a male flowering of maize at 63 days after semi. Maize treated with 60 kg of phosphorus ha−1formed very few or almost no blisters in the roots. Cob weight, length, diameter, number of rows and kernel weight varied significantly with phosphorus on both inoculated and uninoculated pots. The inoculated plants had high averages for these yield parameters. Due to the lack of phosphate fertilizer, inoculum alone can be an alternative to phosphorus provided that nitrogen and potassium are added, resulting in small but seed-filled ears compared to the phosphorus-free control without mycorrhizae, which resulted in empty ears. Yield varied significantly with the addition of phosphorus (0.3 to 6.1 tons ha−1) and less significantly with inoculum (3 to 3.7 t ha−1). The combination of treatments showed a significant difference in favour of the 60 kg of phosphorus or 60 kg of phosphorus associated with the inoculum. The highest phosphorus content was obtained on the inoculum treatment alone, which provided 1.4 mg phosphorus g−1maize compared to other treatments, which provided 0.69 to 0.71 mg phosphorus g−1maize.