Soil fertility is one of the main constraints to agricultural intensification in Ethiopia. Like in many East African countries, nutrient depletion rates are exacerbated in Ethiopia by high erosion rates, biomass and animal manure removal from farm plots and limited application of mineral and organic fertilizers. In this paper, soil nutrient balances at plot level were calculated for 350 farms spread across the high potential highlands of Ethiopia. The nutrient input flows and output flows were monitored over a period of 3 years (2012-2014) using the monitoring for quality improvement toolbox. Average nitrogen (N), phosphorus (P) and potassium (K) balances were -23 ± 73, 9 ± 29 and -7 ± 64 kg ha -1 , respectively. The situation was most severe for N, where average depletion rate was 0.2 % of the soil total N stock per year, which equals about 4.2 % of the available soil N pool. Depletion rates were highest in the relative intensive farming systems in mountainous areas located in the central and southern parts of Ethiopia. Nutrient depletion rates increased in time with 13, 3 and 10 kg ha -1 year -1 , respectively for N, P and K during the monitoring period. The Ethiopian government responds to the on-going, and worsening, soil nutrient depletion by stimulating the use of mineral fertilizers. We conclude that the current efforts on increased inputs of mineral fertilizers are a step in the good direction, but to really halt and reverse soil fertility decline, organic fertilizer application and soil and water conservation should be an integral part of the intervention strategy.

Despite the fact that maize productivity is relatively better than other major cereal crops, its current productivity is still far below its potential productivity. N rate and time of application are among the major abiotic factors limiting the productivity of the crop. Because of such gaps, the experiment was conducted at Bako Agricultural Research Center in 2013 and 2014 cropping seasons to determine optimum N rate and time of application. Four levels of N rates (46, 69, 92, and 115 N kg ha −1 ) and four levels ( 1 , 2 , 3 , and 4 ) of different time of N application were arranged in factorial combinations. Moreover, previously recommended N and the control were arranged in a randomized complete block design with three replications. In 2013, the highest significant biomass yield (21.2 tha −1 ) was obtained at 115 N kg ha −1 and 4 followed by 69 N kg ha −1 at 1 and 2 and 92 N kg ha −1 at 2 . In contrast, the highest grain yield in 2013 was obtained at 92 N kg ha −1 at 2 followed by 115 N kg ha −1 at either 2 or 4 and 69 N kg ha −1 at either 1 or 3 application time. Interestingly, a significant yield increase by 37% was obtained when 92 N kg ha −1 at the time of 2 was applied compared to previous recommended 110 N kg ha −1 rate and time of application. In 2014, however, the highest yield was recorded when 92 N kg ha −1 at 1 was used. Application of 46 N kg ha −1 at 2 showed statistically similar yield performance when compared with previous N recommendation. The lowest yield was recorded from the control plot in both years. In 2013, the maximum net profit and acceptable marginal rate of return (MMR) were obtained when 92 N kg ha −1 at 2 was used for maize production during erratic and heavy rainfall distribution, particularly at a time of N application. However, the maximum net benefit (30743 ETB ha −1 ) and acceptable MRR could be obtained when 92 N kg ha −1 at 1 was used if the rainfall amount and distribution are relatively uniform. In conclusion, application of 92 N kg ha −1 at 1 (10-15 DAP and 35-40 DAP) is the best N rate and time of application in good rainy seasons and hence recommended for the end users. However, in the case of erratic and heavy rainy seasons, application of 92 N kg ha −1 at three times application regimes (1/3 N at 10-15 days after planting (DAP), 1/3 N at 35-40 DAP and 55-60 DAP) should be used to get maximum profit and acceptable MRR.

Ethiopia is the leading wheat producer in Sub‐Saharan Africa, and the productivity has increased in the last few years. There is also a potential for irrigated wheat production in the lowlands, even though its cultivation is at infant stage. The experiment was conducted in the Oromia region at nine locations in 2021 with irrigation. The study aimed to select high yielding and stable bread wheat variety/ies for lowland areas. Twelve released bread wheat varieties were tested using randomized complete block design with two replications. Environment had the largest effect, 76.5% of total variability, while genotypes 5.0% and GE interaction 18.5% explained total sum of squares. The average grain yield of varieties across locations ranged from the lowest 1.40 t ha−1 at Girja to the highest 6.55 t ha−1 at Daro Labu, with a grand mean of 3.14 t ha−1. The result showed that varieties released for irrigated areas, Fentale 1, Ardi, and Fentale 2, were ranked the top three based on overall environment mean grain yield. The first and second principal component account 45.5% and 24.7% of the genotype by environment interaction (G × E), respectively, explained 70.2% of the total variation. Daro Lebu and Bedeno were the most productive environment, while Girja was the least productive of irrigated bread wheat for lowlands of the Oromia region. Genotype Selection Index (GSI) showed that varieties Fentale 2, Fentale 1, Pavon 76, and ETBW9578 are stable and high yielding. Based on AMMI and GGE biplot analysis, Girja indicated the most discriminating area and Sewena as representative environment for selecting wide adaptable irrigated lowland varieties. The results of the present study indicated that Fentale 2 and Fentale 1 showed better yield stability across all test environments, therefore, these bread wheat varieties are recommended for wide cultivation in irrigated areas of the Oromia region.

Wheat is among the cultivated and important crops in Ethiopia because of its high value as a stable food that is mostly grown under rain-fed conditions. Even though the country has the potential to produce a sufficient amount of wheat grain under rain-fed and by using irrigation, the country still depends on importing wheat grain every year. Soil fertility depletion, inappropriate agronomic practices, erratic rainfall, and drought are among the constraints to the low yield of wheat crops in the country. In view of this, the field experiment was conducted during the off-season of 2020 in five districts, namely, Horo, Jimma Geneti, Jimma Arjo, Wayu Tuka, and Degem districts that are selected as representatives in terms of agricultural production and irrigation potential. The treatments consisted of five N fertilizer levels (0, 23, 46, 69, and 92 kg·ha−1) and three seeding rates (125, 150, and 175 kg·ha−1) of bread wheat, which constituted a total of 15 treatments. The experiment was laid out in a randomized complete block design with a factorial arrangement in three replications. The plot size was 3 m × 5 m. From the study, we observed that the grain yield and yield components of wheat were improved by optimizing nitrogen application and plant population. Maximum grain yield of 6.8, 8.9, 4.1, 4.8, and 2.5 t·ha−1 was recorded in response to the use of 92/125, 23/150, 23/150 and 175, 69/150, and 69/175 kg·ha−1 N/seed rate of wheat under irrigation condition in Horo, Jimma Geneti, Jimma Arjo, Wayu Tuka, and Degem districts, respectively. On the contrary, the lowest yield was observed from the unfertilized plot that was planted at 125 kg·ha−1 seed rate in all districts, except in Jimma Geneti, which was observed at 0/150 kg·ha−1 N/seed rate. The differences in yield between districts are mainly attributed to the variability in their soil-plant nutrient contents. Thus, N fertilizer and seed rates at 23/150, 69/150, 46/50, and 92/125 kg·ha−1 in Jimma Arjo and Jimma Geneti, Wayu Tuka, Degem, and Horo districts, respectively, gave maximum yield and net benefit with acceptable marginal rate of return, and it is economically feasible and the best rate to use by the end-users in bread wheat production under irrigation condition in the study area and agro-ecologies that are similar to the study area.

Background and Objective: The population growth and changing food preferences in Ethiopia have resulted in an increasing demand for wheat which results in the expansion of irrigated wheat production to ensure food self-sufficiency. This expansion of irrigated wheat production for sustainability needs the identification of potential stakeholders with their roles and constraints. Besides, Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis is also very important. Materials and Methods: The study was conducted at Jimma, Bunno Bedelle and East Wollega Zones of Western Oromia. Focus group discussions and key informant interviews with farmers, experts and unions were used. Descriptive statistics were employed to analyze the collected data. Results: Further expansion constraints like unavailability of inputs with skyrocketing prices, poor irrigation schemes performance, biotic stresses, insufficient farmersʼ skills and knowledge of the technologies, lack of financial sources, lack of local reliable market and shortage of modern schemes were identified as the major constraints to irrigated wheat production. The SWOT analysis has been done, showing the strengths, weaknesses, opportunities and threats of irrigated wheat production. Conclusion: This new initiative knowledge should be useful through developing a regular input supply system, improving farmerʼs skills and knowledge, credit access to farmers, developing modern schemes, developing new disease-resistant varieties and strengthening market linkage by experts, policymakers, researchers and seed enterprise for better orienting investments on irrigated wheat production.