Effect of Irrigation Scheduling and Nitrogen Levels on Yield and Water Productivity of Wheat (Triticum aestivum) at Ambo, West Shoa, Ethiopia
Year: 2024
Type: article
Abstract: Excessive fertilizer use and improper irrigation scheduling can accelerate soil degradation and increase the nitrogen leaching rate. This study, conducted at the Ambo Agricultural Research Center during the 2021/22 and 2022/23 irrigation seasons, aimed to identify optimal nitrogen fertilizer rates for wheat production under irrigation. The experiment followed a randomized complete block design with three replications, utilizing a split-plot arrangement. The main plot tested three soil moisture depletion levels: 80%, 100%, and 120%, while the sub-plot involved five nitrogen levels with 0, 46, 69, 92, and 115 kg N/ha. Results showed that nitrogen levels significantly influenced grain yield, above-ground biomass, and water productivity but not the irrigation regimes or their interaction with nitrogen levels. The 115 kg N/ha rate produced the highest grain yield, 5213 kg/ha, and water productivity of 1.24 kg/m³, though these values were not significantly higher than those at 92 kg N/ha. Both 115 kg and 92 kg N/ha treatments significantly outperformed the 69 kg N/ha treatment and lower rates. Applying 120% allowable soil moisture depletion levels resulted in high net income and benefit-to-cost ratio values of 197,716.00 Ethiopian Birr (ETB) and 30.89%, respectively. At 120% allowable soil moisture depletion, the highest net income and benefit-cost ratio were observed (197,716 ETB and 30.89%, respectively). The 92 kg N/ha application resulted in the highest marginal rate of return (826.05%), well above the acceptable threshold of 100%, with a net income of 223,655 ETB. Based on grain yield, water productivity, and economic feasibility, we recommend applying 92 kg N/ha with 120% ASMDL for wheat production in this region.
Authors: Selamawit Bekele, Oli Frrisa, Kalkidan Degefa
Institution: Ethiopian Institute of Agricultural Research
Language: English
Subfield: Soil Science
Domain: Life Sciences
Open Access status: hybrid
OpenAlex ID: W4404129219