Abstract

An experiment was conducted on farmer's fields during the main cropping season of 2016/2017 in Adiyo district, Southwestern Ethiopia to optimize fertilizer rate recommendation for major cereal production systems by using bread wheat (Triticum aestivum L.) as test crop. Experiment was laid out in a randomized complete block design (RCBD) with three replications for sixteen treatments. The grain yield and yield components were all elevated remarkably by applying different rates and types of fertilizers; five levels of N (0, 23, 46, 69 and 92 kg ha-1); four levels of P (0, 10, 20 and 30 kg ha-1); and four levels of K (0, 10, 20 and 30 kg ha-1). In addition, the last three diagnostic treatment foliar applications 45 days after planting and compared with control (absolute zero) treatment was done. Yield and yield components were measured using the SAS statistical package program version 9.3. The least significant difference (LSD) at 5% probability level was used to establish the difference among the means. To investigate the economic feasibility of the fertilizers, partial budget, dominance analysis and marginal rate of return were used. There was significant difference in grain yield and yield components of bread wheat (danda‘a variety) among the treatments. As the results showed high biological yield response recorded under 92N20P20K kg ha-1 (5.62 t ha-1) and the lower yield response was under control treatment (4.09 t ha-1); but high economic yield response recorded under 23N20P kg ha-1 (5.20 t ha-1). In conclusion, the fertilizers containing nutrient rate of 23N20P (kg ha-1) had brought the higher economic net benefit (27409.99 ETB/ha) with MRR (92.61%) and showed efficient use of fertilizer. Therefore, based on the biological yield response and economic net benefit, it is recommended to apply 23N20P (kg ha-1) fertilizers at Adiyo district, Southwestern Ethiopia and areas with the same soil conditions and agro-ecology.

Key words: Economic analysis, foliar application, wheat yield, nutrient type, rate.