The influence of soybean genotypes with different maturity groups on the symbiotic effectiveness of Bradyrhizobium spp under high native soil N is not well known. Therefore, the objective of this work was to evaluate the influence of maturity time of soybean genotypes on the symbiotic effectiveness of Bradyrhizobium spp. at higher soil N. Three isolates of Bradyrhizobium spp. (UK-isolate, TAL-379 isolate and local-isolate) and six soybean genotypes, three late maturing (Wogayen, TGx-1336424 and Belsa) and three medium maturing (GIZA, Afgat and Gishame) were used for greenhouse experiment. Only GIZA and TGx-1336424 were selected for field experiment. The result of the experiments showed that significantly (P < 0.05) differences in all investigated traits, except total plant tissue N, was observed in TGx-1336424 with UK-Isolate and Local-Isolate.TAL-379 inoculation performed better in all investigated traits of GIZA genotype than other inoculation treatments. N-fertilization in the greenhouse experiment significantly (P < 0.05) improved the shoot biomass of Wogayen and Belsa-95, but did not observe in GIZA and Gishame. The regression analysis obtained between nodule number and nodule dry weight with that of grain yield indicated generally higher R2 value for late maturing than that of the medium maturing genotypes. This indicates high importance of nodulation for improving the GY of late maturing genotypes. Hence, this study proves the need for inoculation to improve the production and productivity of soybean sustainably in Ethiopia, with particularly pronounced effect on late maturing genotypes of soybean.

Background: Effectiveness of Rhizobium inoculation is determined by common bean genotypes. Environmental factors also affect common bean genotypes-Rhizobium-symbiosis. The effect of common bean genotypes-Rhizobium strains-environment interaction on nodulation and common bean production is not well studied. Three genotypes (Dursitu, Gofta, and Kufanzik) and eight selected isolates of common bean nodulating-rhizobia with N-fertilized and control check were used for field experiments at four locations (Babile, Fedis, Haramaya, and Hirna) to evaluate the effect of genotypes-Rhizobium strains-environment interaction on the nodulation, yield and yield traits of common bean. The treatments were laid out in a randomized complete block design with three replications.Results: This study revealed that Rhizobium inoculation, the genotypes, environment and their interaction significantly (P ≤ 0.05) affected all investigated traits of common bean. Common bean genotypes Rhizobium inoculation and experimental locations significantly affected nodule number (NN) and nodule dry weight (NDW). The highest NN and NDW as compared to the uninoculated control across locations were recorded with the genotype Dursitu in all inoculation treatments. However, the result revealed the lowest mean total biomass (TBY) and grain yield (GY) over locations with the same genotype Dursitu. The highest mean grain yields of 3358.89, 3257.82, 1499.25 and 2204.82 kg ha −1 across the treatments were recorded at Haramaya, Hirna, Babile and Fedis sites, respectively, with the genotype Gofta, thereby implying that there was none specificity between common bean genotypes × locations in the study locations of eastern Ethiopia with tested common bean genotypes. None of the tested isolates produced statistically better NN, NDW, TBY, GY and total plant N accumulation consistently in all locations with all tested common bean genotypes, indicating the presence of Rhizobium strains × location specificity. Conclusion: Therefore, the result showed the need for a specific strain of Rhizobium development for common bean production in different locations.

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Purpose An investigation was carried out to evaluate the effect of the integrated application of organic and inorganic fertilizer effect on Bradyrhizobium effectiveness on nodulation and yield of peanut at the major growing areas of Eastern Ethiopia, Babillae and Fedis sites. Methods Systemic combination of compost, manure, Bradyrhizobium inoculation and NP application was laid out in Randomized Complete Block Design with three replications. Results The result showed that Bradyrhizobium integrated with organic inputs significantly improved the nodule number at Babillae while Bradyrhizobium when applied with DAP resulted in a significant increase of nodulation at Fedis site. The highest total biomass and total pods weight at both sites were found to record when Bradyrhizobium integrated with manure and compost. Integration of Bradyrhizobium, manure and compost at Fedis and Bradyrhizobium with manure at Babillae was found to increase the kernel yield by 44 and 66.6% over the control check, respectively. Integration of Bradyrhizobium, manure and compost at Babillae and Bradyrhizobium with starter N at Fedis significantly increased plant N accumulation. The effect of organic and inorganic application on soil N and organic carbon content was not significant at Fedis, but the slight increase was observed in Babillae site. A significant increase in the soil available P by organic and/or DAP application was found in either of the experimental sites. Conclusion Organic fertilizer when integrated with Starter N and DAP is better in improving the effectiveness of Bradyrhizobium, nodulation and yield of peanut in either of the sites.

Background: Due to common bean derives lower nitrogen (N) from symbiotic N 2 -fixation, it requires N either from inorganic fertilizer or soil N. Field experiments were conducted at four locations to evaluate the effect of Rhizobium leguminosarum bv. phaseoli inoculation on agronomic efficiency of N of common bean var. Dursitu major growing areas of eastern Ethiopia. ) and two inoculation treatments (uninoculated and inoculated) were factorially combined and laid out in randomized completely block design, replicated three times. . The highest AE-Ns at Babillae, Fedis and Haramaya sites were obtained from 20 kg N ha −1 applied with Rhizobium inoculation while 40 kg N ha −1 supplied with Rhizobium inoculation at Hirna site. Regardless of experimental sites, inoculation improved AE-N. A positive relationship between AE-N and NDW was also observed in all experimental sites. Significant increase in grain yield with increasing rates of N application was also observed. Methods Results Conclusion:Hence, it can be concluded that inoculation is recommendable to increases the efficient utilization of applied Mineral N.

Background: Bacterial bioinoculate is one of environmentally friendly input for crop production. Several works revealed that effectiveness of Rhizobium bioinoculant have been affected by the native rhizobia population. Hence, this study was initiated to evaluate the effect of selected Bradyrhizobium in nodulating peanut in the major growing areas of Ethiopia. Methods:The effect of eight effective Bradyrhziobium vis-a-vis 20 kg N ha −1 and the control check on the nodulation and yield of two peanut cultivars (Sedi and Werer 942) at Babile and Fedis, eastern Ethiopia, during 2013 cropping season was evaluated. Results:The results showed that the inoculation, location and cultivar and their two and three ways interaction had a significant influence on the nodulation and grain yield. Inoculation of Bradyrhizobium increased the nodule number, nodule dry weight, number of seeds per plants, total pods weight, hundred seeds weight, total biomass yield, grain yield and shelling % up to 37, 24.9, 22.4, 22.5, 5.5, 26.2, 35.8 and 24.1%, respectively. Isolate HUGNR-29 was found to be more effective as it scored the highest nodule dry weight and grain yield. Application of inorganic N increased the yield and yield components of peanut in either of locations. Though the statistically better effective nodule % was recorded at Babile, significantly higher nodule number, nodule dry weight, and total N accumulation were obtained from Fedis than Babile site. Significantly higher total pods weight, hundred seeds weight, total biomass weight, grain yield and total plant N accumulation was recorded with the cultivar werer-962 than those produced with Bati-Sedi. Conclusions:The result showed that Bradyrhizobium inoculation is essential to improve the peanut production through environmentally and economically sustainable ways though the soil native rhizobia nodulating peanut was high. Peanut cultivar and study site based rhizobia inoculant development is also important.

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Purpose This experiment was initiated to evaluate the effect of filter cake and bagasse ash on the productivity of wheat under greenhouse conditions. Methods Six levels of filter cake and bagasse ash each separately and control check were arranged in a completely randomized design with three replications. Results At 100 tons/ha, both inputs resulted in the highest values of all the investigated traits. It was also found that yield and yield components that were obtained from bagasse ash overwhelmed those from filter cake treatments, except in tillers, dry biomass, and straw yield. Linear regression analysis revealed a significant and positive relationship between grain yield with that of total N, P, K, S, Ca, Mg, Cu, and Zn uptake. A linear relationship between the grain yield with that of N and Zn uptake was found, while the association between grain yield with total P, K, S, Ca, Mg and Cu uptake was quadratic. Conclusion It can be concluded that filter cake and bagasse ash are good sources of nutrients to enhance wheat yield in acidic soil. To give a conclusive result, these inputs should be tested in field trials in different soil types.