The potential role of Abuscular Mycorrhizae and native rhizobia in upscaling maize and cowpea production in semiarid zone of Eastern Kenya

Legumes are an essential component of many cropping systems due to their ability to form symbiotic associations with nitrogen fixing bacteria. Key constraint faced by smallholder farmers in Sub-Sahara Africa is lack of resources so they cannot afford Nitrogen fertilizers. Soil microorganisms especially rhizobia and Arbuscular mycorrhizae fungi form tripartite symbiosis and enhance nitrogen fixation, uptake of essential nutrients such as phosphorus and protect plants against biotic and abiotic stress. The study was carried out to determine effect of native rhizobia nodulation in different cowpea genotypes and Arbuscular mycorrhizae fungi colonization potential in different maize genotypes. Ten farms were selected from Embu and Kitui Counties in Eastern Kenya (five farms in each county respectively). Four genotypes of cowpea and maize were selected as the trap host. A greenhouse experiment was setup and treatments were set out in randomized complete block design that was replicated four times. After four weeks the plants were harvested and nodule number and dry weight were recorded. The maize was also harvested at the same time and mycorrhizae colonization in the maize roots determined. Cowpea nodulation was significantly (p<0.0001) different among genotypes and soil source. The open pollinated cowpea varieties had the highest nodulation ranging from 39.35 to 40.58 and the landrace used had the lowest nodulation (30.35). Arbuscular mycorrhizae colonization was significantly (p<0.05) different among the test genotypes.