Evaluation of Different NP Fertilizer Rates and Bradyrhizobium Inoculation on Yield and Yield Components of Soybean [Glycine Max (L.) Merrill], at Jinka, Southern Ethiopia
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- Bradyrhizobium, Inoculation, Nitrogen Fertilizer, Phosphorous Fertilizer, Soybean
- Yoseph, Tekle; Worku, Walelign
- This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. CC BY-NC-SA 4.0 Creative Commons License: https://creativecommons.org/licenses/by-nc-sa/4.0/
- A field experiment was carried out at Jinka Agricultural Research Center to determine the effect of NP fertilizers application rate and bradyrhizobium inoculation on yield and yield components of soybean [Glycine max (L.) Merrill] in 2008 under rain fed condition. The experiment was conducted with two levels of nitrogen in the form of urea (0 and 46 kg ha-1), two levels of bradyrhizobium (0 and Str-TAL-379) and four levels of phosphorous fertilizer in the form of TSP (0, 25, 50 and 75 kg ha-1). The experimental design was split-split plot with four replications where, N was arranged as main plot factor, bradyrhizobium and P were arranged as sub and sub-sub plot factors, respectively. Phenological and growth parameters such as yield and yield components, total biomass, harvest index were studied. The result showed that all phenological and growth parameters except number of branches per plant were significantly affected by nitrogen fertilization. The number of days required to reach at each of the phenological stages were delayed as nitrogen was applied. Application of nitrogen increased both plant height and leaf area index. Grain yield and pods per plant were significantly affected by nitrogen application. The grain yield obtained from 46 kg N ha-1 application (1.39 t ha-1) was higher by 25.23% compared to 0 kg N ha-1(1.11 t ha-1). Both total biomass and harvest index were significantly influenced by nitrogen application. Inoculation did not affect significantly phonological and growth parameters except flowering and pod setting dates. Inoculation did not bring significant variation on grain yield but it affected significantly yield components except number of pods per plant. Inoculation had significant affected total biomass and harvest index. The highest total biomass (3.16 ton ha-1) and the highest harvest index (0.54), obtained from inoculation were 25.40% and 31.71% increase over non inoculated treatments, respectively. All the phenological, and growth parameters except number of branches per plant were significantly affected by phosphorus fertilization. Phenological stages of soybean were reduced as the level of phosphorus increased. Phosphorus application significantly affected grain yield, yield components and harvest index but it did not affect significantly total biomass. The highest grain yield (1.42 t ha-1) was obtained from the highest phosphorus rate of 75 kg P ha-1 showing 59.55% increase over 0 kg P ha-1. The highest grain yield from 75 kg P ha-1 was contributed by increased number of pods per plant and heavier seed weight. There was no significant interaction between nitrogen fertilizer, inoculation and phosphorous fertilizer for all studied parameters except days to pod setting, plant height, and number of pods per plant and harvest index. Application of 46 kg N ha-1, inoculation or P fertilization of 25 kg P ha-1 resulted in higher net benefit and maximum MRR (%). Therefore, it can be concluded from this result that nitrogen application of 46 kg N ha-1, inoculation or phosphorous application at the rate of 25 kg P ha-1 is advisable and could be appropriate for soybean production in the test area even though further testing is required to put the recommendation on a strong basis.
Full text: IJRAS_615-01_Final.pdf