OPTIMIZED INORGANIC FERTILIZER APPLICATION ON SORGHUM YIELD AND NITROGEN USE EFFICIENCIES IN THE NIGERIAN SAVANNA

Project Abstract

In the Nigerian savanna, optimizing inorganic fertilizer application for sorghum production is crucial for maximizing yields and improving nitrogen use efficiencies. This research project aims to investigate the effects of different rates of inorganic fertilizer application on sorghum yield and nitrogen use efficiencies in the Nigerian savanna region. The study will involve field experiments conducted in different locations across the savanna to assess the response of sorghum to varying levels of nitrogen fertilizer. The research will focus on determining the most effective rates of nitrogen fertilizer application that can enhance sorghum yield while improving nitrogen use efficiencies. Various parameters such as grain yield, biomass production, nitrogen uptake, nitrogen use efficiency, and nitrogen recovery efficiency will be measured and analyzed to evaluate the impact of different fertilizer rates on sorghum growth and development. Through this research, valuable insights will be gained into the optimal nitrogen fertilizer application rates for sorghum cultivation in the Nigerian savanna. The findings will contribute to sustainable agricultural practices by providing farmers with science-based recommendations for maximizing sorghum yields while minimizing nitrogen losses to the environment. Additionally, the study will help in understanding the nutrient dynamics in sorghum production systems in the savanna region, leading to improved nutrient management strategies for enhancing crop productivity and environmental sustainability. Overall, this research project will provide valuable information on the optimized inorganic fertilizer application for sorghum cultivation in the Nigerian savanna, ultimately supporting efforts to ensure food security, increase agricultural productivity, and promote sustainable farming practices in the region.

Project Overview

<p> </p><p><strong>1.0 INTRODUCTION</strong></p><p>Sorghum (<em>Sorghum bicolar</em>&nbsp;(L.) Moench) is an important staple food grain among many smallholder farmers of the Nigerian savanna (Ofor <em>et al</em>., 2009). It occupies about 44% of the total land area devoted to cereals in Nigeria (Ajeibe <em>et al</em>., 2010). The land area put into cultivation of sorghum in Nigeria is 6.7 million hectares (FMARD, 2012b).</p><p>Decline in yield has been identified as major constraint to sorghum production. Average yield is estimated at 0.6-1.7 tons per hectare against potential yield of 4.0-5.0 tons per hectare of sorghum (FMARD, 2012b). The yield gap is attributed to poor inherent soil fertility and low fertilizer use. (Vanlauwe and Giller, 2006). Smallholder farmers apply little to no fertilizer to their land due to socioeconomic factors including timely access to fertilizer (SSA-CP, 2005). Improper types of fertilizers, ineffective extension system and inappropriate fertilizer recommendation which limit the efficiency of fertilizer use reduce farmer‟s income and increase poverty and food insecurity in the Northern Guinea Savanna of Nigeria (SSA-CP, 2005).</p><p>Nitrogen use efficiency (NUE) is important in developing fertilizer recommendations for profitability and environmental sustainability (Kaizzi <em>et al</em>., 2012). Low nitrogen use efficiency in crop production is due to excess application of N. Deficiency of phosphorus (P) and other essential nutrients limit crop growth due to biotic and abiotic factors (Bekuda <em>et</em>&nbsp;<em>al</em>., 2007; Kaizzi<em>&nbsp;et al</em>., 2012). Several attempts to provide fertilizer recommendations tosmallholder farmers often lead to inappropriate fertilizer rates that lower the NUE of crops.</p><p><strong>1.1 Justification of the Study</strong></p><p>Current fertilizer recommendations are aimed at maximizing yield rather than profit. The fertilizer rate needed to maximize net returns is a function of fertilizer cost relative to grain prices as the fertilizer prices increase relative to the prices, the economic optimal rate (EOR) is expected to decrease. Therefore, they need to maximize net returns for a given amount of money they have to invest in fertilizer which can be maximized by identifying the right combinations of nutrient, and application rate that will give highest value to cost ratio (VCR).</p><p><strong>1.3 Objective of the Study</strong></p><p>The general objective of this study was to provide recommendations for optimizing crop yield and profit from fertilizer use for financially constraint and small holder sorghum farmers in the northern guinea savanna zone of Nigeria. The specific objectives are:</p><ul><li>To evaluate the yield response of sorghum to N, P and potassium (K) at the selected sites in the Northern Guinea Savanna of Nigeria.</li></ul><ul><li>To determine the economically optimal nutrient rate for N, P and K and the corresponding value to cost ratio (VCR) at different fertilizer cost to grain price ratio.</li></ul><ul><li>To determine the N use efficiency (NUE) of sorghum at the selected sites in the Northern Guinea Savanna of Nigeria.</li></ul> <br><p></p>