Influence of Nitrogen Rates and Row Spacing on the Yield of Barley (Hordeum vulgare L.) in Sudan (Kebbi State) and Guinea (Niger State) Savanna Zones of Nigeria

Abstract Barley is the world`s fourth most important cereal crop after wheat, rice and maize. It is grown throughout the temperate and tropical region of the world and is usually used as food for human beings and feed for animals. Its productivity is constrained by a number of problems, among which are poor nitrogen fertilizer scheduling and inappropriate spacing which poses a serious setback to barley productivity. Based on these, two multi-locational field experiments were conducted simultaneously during the 2024/2025 dry season at the experimental Research fields of the National Cereals Research Institute Badeggi, in Niger State, Nigeria, and the Sub-Station of the National Cereal Research Institute, located in Birnin-Kebbi, Kebbi State Nigeria (The aim was to assess the yield of barley as influenced by nitrogen rates and row spacing. The experiment consisted of four levels of nitrogen (0 kg N ha⁻¹, 60 kg N ha⁻¹, 120 kg N ha⁻¹ and 180 kg N ha⁻¹) and three levels of inter-row spacing, (15cm, 25cm and 35cm) arranged in a Randomized Complete Block Design (RCBD) with three replications. The result showed that the application of 120 kg N ha⁻¹ significantly produced the highest mean values of days to 50% heading, panicle number, grain yield per plot and 1000-grain weight, which were significantly higher than other fertilizer rates. The least mean value for the yield parameters were recorded in the control. Higher mean values were obtained in the 25 cm. Based on the result obtained, the application of nitrogen at 120 kg N ha⁻¹, coupled with adoption of 25cm inter-row spacing could be recommended for best barley production at both agro-ecologies of Niger and Kebbi States. Keywords: Barley, Inter-row spacing, Nitrogen, Savanna zones of Nigeria, Yield.