Despite the importance of soyabean in Nigeria, yields on farmers’ fields have remained relatively low. The crop holds considerable potential for arresting soil fertility decline and enhancing household food nutrition. Therefore, this study aimed to exploit differences among soyabean genotypes, assess genotype environment effect on seed yield and rhizobia inoculation as a means of improving nitrogen fixation and productivity of soyabean across three locations in the savanna region of Nigeria.

Common bean seed multiplication

In order to examine the interaction between bean genotypes and rhizobium strains nodulating bean, seed of 29 different bean varieties that represent a great genetic diversity were obtained from CIAT, Colombia. They were multiplied in a screenhouse on soil samples collected from potential bean growing areas in Sidama, Ethiopia.

A lot has happened since last year: the first paper of my PhD, entitled Understanding variability in soyabean yield and response to P-fertilizer and rhizobium inoculants on farmers’ fields in northern Nigeria got published in Field Crops Research (Podcaster 34), I largely finished the data collection in Uganda and I have entered the final year of my PhD, so I will focus on writing up the results.

The aim of my study is to unravel the contributions of genetic, environmental and management related factors to common bean yield and nitrogen fixation. I am conducting a continuous cropping study, which involves rotations and intercropping of common bean with maize for six seasons and compare the performance of two bean varieties; namely improved Lyamungu 90 and local Mkanamna.

This study examined the impact of improved cowpea varieties on the income and the food security status of women farmers in southern part of Borno State, Nigeria. The study used data on farmers before the Promoting Sustainable Agriculture in Borno State (PROSAB) project started in 2004 and after the project folded up about ten years after in 2015.

The aim of my study is to explore the use of rhizobia inoculation in order to increase yield and biological nitrogen fixation of the selected groundnut genotypes in the Sudan and northern Guinea savannas of Nigeria. Last year, I have already started the field work with two experiments. The first experiment included the following treatments; six groundnut varieties and six different inoculants treatments (NC 92, SBG 234, MJR 518, WDL 129, +N (20 kg N ha ^-1), and -N (0 kg N ha^-1)).

Rhizobia inoculants form the backbone of soyabean production, which is important in Zimbabwe’s agriculture led economy. Traditionally, soyabean production is carried out with the use of elite, but exotic, rhizobia inoculant strains. It has been established in previous studies (Zengeni et al., 2003; Zengeni et al., 2006) that these strains do not persist well in the fields, and require frequent inoculation.

Genetic and symbiotic characterization of indigenous rhizobia

The aim of my study is to unravel the types, nature, genetic diversity and effectiveness of groundnut-nodulating rhizobia existing in different soil types of the moist; northern Guinea (NG) and dry; Sudan (S) savannas of Nigeria, with a view to identify strains that hold promise for improved symbiotic N₂-fixation, productivity and soil fertility.