Lentil plays a major role in the food and nutritional security of low income Ethiopian families because of the high protein content of their seed; however, their productivity typically is low largely due to soil fertility limitations. Field and pot experiments were conducted during the 2011 cropping season to determine the effectiveness of Rhizobium strains on two cultivars of lentil in Southern Ethiopia. Six rhizobial inoculant treatments (four indigenous and two commercial inoculants), a nitrogen (N) fertilizer treatment (50 kg·urea·ha⁻¹) and an absolute control (non-inoculated non-fertilized) were used. Inoculated plants produced significantly higher nodule number, nodule dry weight, grain yield and yield components than non-inoculated non-fertilized plants. Inoculation of field grown lentil with rhizobia strain Lt29 and Lt5 enhanced seed yield by 59% and 44%, respectively. Whereas urea fertilization enhanced yields by 40%. Similarly, grain yields were increased during the pot experiment by 92% and 67% over the control treatments by inoculation with Lt29 and Lt5, respectively. The highest levels of N fixation were achieved in plants inoculated with Lt29 (65.7% Ndfa). Both field and pot investigations indicate that inoculation of lentil with native rhizobial strains replace the need for inorganic N fertilization to optimize lentil yields.

A series of pot and two consecutive crop-year field experiments were conducted from 2011 to 2012 in Southern Ethiopia to determine the effectiveness of Mesorhizobium strains on two cultivars of chickpea (Shasho and Nattoli). The eight treatments included: Six rhizobial inoculants, the four best indigenous strains (Cp8, Cp41, Cp97 and Cp105); CpNSTC (National Soils Testing Center inoculant); and CpSK (Canadian inoculant), Nitrogen fertilizer and a control. The results from the field and pot experiments indicated that chickpea crop yield can be improved using proper Mesorhizobium inoculation. Inoculation had a pronounced effect on grain yield, yield component, total N uptake, grain protein content, percentage N derived from the atmosphere (%Ndfa) for the seed, and amount of seed N fixed compared to non-inoculated treatments. In the pot experiment, significant difference was recorded among the mesorhizobial strains used with the indigenous strain Cp41 highly effective in shoot dry weight (41%) mg-1 plant, grain yield (50%), total N uptake (117%), and %Ndfa (67.9%) followed by CpSK, Cp8 and Cp97. In the second crop-year field experiment, the indigenous Mesorhizobium strain Cp41 also proved highly effective in-nodule dry weight (786%) mg-1 plant, grain yield (66%), total N uptake (100%), and %Ndfa (53.7%). The maximum seed protein content was recorded during the second crop-year field experiment in Cp41 (20%), followed by N fertilizer added treatment and CpSK (18%). The chickpea indigenous rhizobial strain Cp41, was superior inoculant for almost all parameters. Thus, there are potential advantages to be gained from using efficient rhizobial inoculants under rain fed conditions in Ethiopia. Key words: Chickpea, rhizobia inoculants, nodulation, growth, yield.

Background: Onion is one of the most important crops widely cultivated throughout the world, including Ethiopia. The production of onion is mainly affected by the inadequate application of inorganic fertilizer types and rates. Objective: A field experiment was conducted to evaluate the effect of nitrogen and sulfur fertilizers on the growth, yield, quality, and nutrient uptake of onion at Shewa Robit in 2018/19 under irrigation. Methods: The experiment consisted of four nitrogen rates (100, 150, 200, and 250 kg N /ha) and five sulfur rates (0, 15, 30, 45, and 60kg S/ha). The treatments were laid out in a factorial arrangement with three replications using randomized complete block design (RCBD). Bombay Red was used as a testing onion variety. Results: The interaction effect of nitrogen and sulfur significantly increased plant height, leaf length, leaf diameter, leaf area index, neck diameter, shoot dry weight, bulb fresh weight and bulb dry weight, percent dry matter content, yield, and quality parameters. The application of 200kg N/ha and 45 kg S/ha resulted in the highest yield (42.6 t ha^-1), the average weight of bulb (193.6g), and a marketable bulb (99.8%). The highest N uptake (243.3 kg ha^-1) and S uptake (31.9kg ha-1) were obtained by the combined application of 200 kgN/ha and 45kg S/ha. Conclusion: The application of 200 kgN/ha and 45kgS/ha can be recommended for high yield and quality onion production in the study area.