• Native rhizobium strains effectively nodulated a popular groundnut variety in Ghana. • Rhizobium inoculation increased biological N2 fixation in groundnut grown in soil. • Ghanaian groundnut strains are genetically related to Bradyrhizobium yuanmingense. • Native isolates are a potential source of strains for local inoculant production.

Inherently low concentrations of soil nutrients and erratic rainfall pattern in sub-Sahara Africa limit soybean response to rhizobia inoculant and P-fertilizer. The study was conducted to: (i) improve soybean response to rhizobia inoculation and P-fertilizer through the addition of organic manure; (ii) enhance rain water use efficiency and (iii) determine the economic viability of combined application of the three factors in soybean cropping systems in the Northern region of Ghana. A factorial experiment with two levels of rhizobia inoculant, two levels of Phosphorus, two different kinds organic manure [fertisoil (a commercially prepared compost from urban waste, rice husks, of poultry manure and shea butter waste) and cattle manure] and a control arranged in randomized complete block design with three replications was established on farmers' fields. The combined application of rhizobia inoculant, P-fertilizer, and organic manure markedly increased nodulation, shoot biomass, haulms, harvest index (HI), P agronomic efficiency (P-AE), and rain water use efficiency (RUE) compared to the control. The combined application of rhizobia inoculant, P-fertilizer, and fertisoil increased grain yield by four-folds whereas the combined application of rhizobia inoculant, P-fertilizer, and cattle manure increased grain yield by three- folds. Harvest index, P-AE, and RUE were relatively higher with the fertisoil treatment combinations than with the cattle manure combinations and the control treatment. The application of rhizobia inoculant, P-fertilizer in combination with fertisoil was profitable with VCR of 2 as compared to the combination of cattle manure which had a VCR of 0.40. The results showed that fertisoil offers a better option of improving soybean response to rhizobia inoculant and P-fertilizer; and has the potential to enhance rain water use efficiency. However, the long term benefit must be quantified.

The need for low‐cost carrier materials is paramount for rhizobium inoculants production, especially in sub‐Saharan Africa. This research studied different feedstocks biochar as potential carriers for inoculant production. Coconut coir (CC), coconut shell (CS), rice husk (RH), and sugarcane bagasse (SB) biochars were used as carriers, and their performance was compared to that of standard industrial peat (control). The biochar and peat carriers were inoculated with two elite Bradyrhizobium strains such as KNUST 1002 and KNUST 1006 and the reference strain BR 3267 (where BR is Bradyrhizobium ). The survival rate of the rhizobia was monitored by determining the number of cells, pH, and moisture content for 24 weeks. In addition, the effectiveness of different inoculated carriers was tested in cowpea ( Vigna unguiculata (L.) Walp) under field conditions via a randomized complete block design with four replications. CC and SB enhanced Bradyrhizobium survival for up to 16 and 20 weeks, respectively, whereas CS and RH promoted strain survival for up to 8 weeks. The viable cell count was highest in the peat‐based inoculant during the 24‐week period. BR 3267 in CC and SB significantly ( p < 0.001) increased the nodule dry weight of cowpea compared to uninoculated control. The highest grain yield (1774 kg ha ⁻¹ ) was recorded for CC, which was 16% greater than the grain yield of the peat‐based inoculant (1524 kg ha ⁻¹ ), although this difference was not significant. CC biochar is a potential carrier for inoculant production in Ghana.

Rice production in Ghana is limited by low varietal choices, which puts farmers at a disadvantage in meeting the market demand for consumers. The objectives of this study were to (i) assess the yield potentials of improved rice varieties developed by the Africa Rice Center (AfricaRice), and (ii) to allow farmers to select improved varieties of their choice based on growth and yield, as observed in the field, in order to ensure a high adoption rate, increase productivity and food security. Two seasons (i.e. 2020 major and 2020–2021 minor) field experiments were conducted at two lowland within the Mankran watershed in the Ashanti region of Ghana. The experiment comprised thirteen (13) improved varieties and two local checks and was conducted using recommended good agronomic practices. The key findings of the study showed that growth and yield parameters vary significantly between varieties across locations. The biplot analysis showed that varieties FARO 66, SAHEL 317, and Amankwatia are the best in the major season while WITA 9, GT 11, ARS-957-BGJ-171-15-D-B, NERICA L36, and AGRA were the best in the minor season at both locations. Farmers’ preference for the varieties was based not only on growth and yield but on resistance to lodging, pests, and diseases. In conclusion, the best performing varieties have demonstrated yield potential which is about 92% higher than the yield of the local checks and can be recommended for adoption by farmers. Future breeding programs on these varieties should include the most preferred attributes by farmers in this study. GRAPHICAL ABSTRACT