On-farm verification trial of soil test based crop response phosphorous calibration study for bread wheat production was conducted in 2019/20 main cropping season in the Horo District of the Horo Guduru Wollega Zone. The trial was initiated to verify phosphorus critical level and requirement factor for bread wheat production in Horo District. The treatments were the control (without phosphorus fertilizer), farmers practice (blanket recommendation) and soil test based recommended phosphorus fertilizer rate (RR). The trial was conducted on six farmers' field across the district. Plot size was 10m * 10m. Soil data before planting and yield data were collected throughout the trial. Soil reaction pH (H 2 O) of all the sites ranged from 4.73 to 5.42 and available P ranges from 1.4 to 12.6ppm. Soil acidity of the experimental sites were amended with lime. Bread wheat grain and biomass yield (kg/ha) were high and significantly (p< 0.01) affected by different fertilizer rates used as treatments. The highest grain yield (2875 kg/ha) was resulted with soil test based phosphorus fertilizer rate recommendation. Economically optimum N (46 kg/ha), critical level phosphorus (10 ppm) and phosphorus requirement factor (11.03 kg/ha) for bread wheat production in the district were gained and recommended during the calibration study. It was significantly higher than the grain yield gained from the farmers' practice (2119.4 kg/ha) and control/without phosphorus fertilizer (1647.2 kg/ha). Similarly, soil test based phosphorus fertilizer rate recommendation was economically optimum and feasible for bread wheat production in the district.

The study was conducted at Negasa area in Guto Gida district to mitigate soil acidity using lime and vermicompost application on bread wheat land use of farmer's field during 2018 main cropping season. The factors studied were four levels of agricultural lime (0, 50, 100 and 150% RR rated based on exchangeable acidity method) applied one month before planting and three levels of vermicompost (0, 2.5 and 5 t ha -1 ) applied two weeks before planting. The treatments were laid out as a RCBD in a factorial arrangement, and replicated three times. Representative soil samples were taken before and after planting. The soil physicochemical properties were analyzed following standard procedures. The soil pH and exchangeable basic cations (Ca and K) were significantly increased by 7.62, 31.16 and 26.08% respectively while exchangeable acidity and exchangeable Mg were significantly decreased by 47.73 and 26.53% respectively due to lime application at a level of 150% RR compared to control. While only exchangeable Mg, K and Na and soil bulk density were improved due to vermicompost application. The interaction effect of lime and vermicompost significantly influenced bulk density and total nitrogen of the soil. Simple correlation analysis among soil properties indicates that soil exchangeable acidity is significantly and negatively correlated with soil pH, exchangeable Ca and Na. It can be concluded that application of lime at the rate of 150% RR improve most chemical properties of acidic soil. Similar effort should be done over years to determine the long-term effect of lime and vermicompost on such acidic soil properties.

Ethiopian government has initiated a wheat self-sufficiency strategies through increasing wheat productivity and expansion of production to the irrigable land areas. This study investigated Cluster based large scale demonstration of irrigated bread wheat production in Wayu Tuka and Jima Arjo Districts. Irrigated bread wheat production and build local capacity for wider adoption of irrigated bread wheat production technologies practices in East wollega Zone were the main objectives of the activity. A total of 487 farmers were addressed in both districts. It was done in well-functioned eight irrigation schemes in Wayu Tuka and one irrigation schemes in Jima Arjo district. Site and farmers were selected possessively based on irrigation and production potential of the commodity, farmers' willingness and accessibility for supervision and input transportation. Improved bread wheat variety of "kingbird" for Wayu Tuka and "Dendea" for Jima Arjo District were planted at a rate of 150 kg/ha on a total land size of 124ha. Extension services such as advisory, inputs, training and field day were delivered and organized for the farmers, extension agents and others. Training was given before the implementation of the activity for a total of 80 farmers, 11 extension agents and 18 agricultural experts. Besides, training advisory services were continuously given for farmers from the land preparation up to threshing. Field day was conducted with a participants of 36 agricultural experts, 15 extension agents and 386 farmers. The maximum grain yield (66.06 qt/ha) was recorded from Goto Cluster in Wayu district. While the over all average grain yield obtained from a hectare of land is accounted 44.22 and 39.5 quintals in Wayu Tuka and Jima Arjo District respectively. Totally, 2435 peoples were benefited either directly or in directly from the implemented irrigated wheat production. Therefore, It is better to strengthen current awareness and should be continued for improving productivity of the crop in a sustainable manner.

Soil test crop response-based P calibration study can give farmers more economic use of fertilizers and better soil management practices. In a view of this, the trial was done in the Abay Choman district on ten experimental farmers’ fields in the first year of the experiment (2018/19 cropping season) to determine the economic rate of N and on twenty farmers’ fields in the second and third years of the experiment (2019/20 and 2020/21 cropping season respectively) to determine phosphorus critical level and requirement factor. In the first year of the experiment, the treatments were combined in factorial with four levels of phosphorus (0, 10, 20, 40 kg/ha) and four levels of nitrogen (0, 46, 92 and 138 kg/ha). While experiments in the second and third years of the experiment were six levels of Phosphorus 0, 10, 20, 30, 40 and 50 kg/ha. The treatments were laid out as a randomized complete block design (RCBD) with three replications. Representative soil samples were taken before planting and analyzed. Experimental sites that have a pH of < 5.5 were amended using the lime application before the setup of the experiment. Soil test results of the study sites before planting indicated that pH values of most soils were strongly acidic (<5.5) and available phosphorus of experimental soil ranged from 3.22 to 13.62 pp. The main effects of both N and P significantly influenced the mean grain yield of maize, but their interaction was not significant with a grand mean of 76.53 qt/ha during the N determination trial. Economic analysis using partial budget analysis showed 92 kg/ha of N was economically optimal for the production of maize in the Abay Choman district. The study also showed that P- the critical value (12 ppm) and P- the requirement factor (10.55 Kg P/ha) were determined for the phosphorus fertilizer recommendation in the study area. Thus, the farmers in the area might be advised to use soil test crop response-based fertilizer recommendations to increase the productivity of maize in and around the study district.

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