Nitrogen Content and Effect of Different Nitrogen Rates and Lime on the Growth and Yield of African Yam Bean (Stephenpstylis stenocarpa)

Moses Ogbaji

Department of Crop Production, University of Agriculture, Makurdi, Nigeria.



Food security and sustainability are serious challenges in Africa. Legumes are the main source of protein since most people cannot afford animal protein. Many indigenous legumes of Africa with potentials to ameliorate nutritional food securities are presently neglected and underutilized. African Yam Bean (Spenostylis stenocerpa) (AYB) is one of such crop with tremendous nutritional value with poor awareness especially its nutritive value, the precise knowledge of factors affecting its growth and yield particularly the use of Nitrogen fertilizers. The nutritive value of AYB including Nitrogen content was therefore compared with cowpea (Vigna unguiculta(L.) Walp) in the laboratory using the methods of AOAC (1995). Kjeldehl method was used to determine the Nitrogen content. Secondly, a field experiment using a 3×3 factorial arrangement in a Randomized Complete Block Design was carried out in 2014 to test the growth and yield response of five varieties of AYB to different Nitrogen and Lime rates.

Results of the study indicated that AYB was as nutritious as cowpea when all the nutrients including Nitrogen were compared. AYB gave a Nitrogen content of 0.096 compared with that of cowpea (0.093). Similarly, 90kgN/ha combined with 90kg Lime/ha better enhanced the growth and yield of different AYB varieties better than all other treatment combinations. The interactive effects between fertilizers and the different accessions of AYB were also significant as far as growth and yield of the crop were concerned. Favourable intensified research findings to encourage the production, wide consumption and general acceptability of AYB are hereby strongly advocated.