Effect of NP Fertilizer Rate and Bradyrhizobium Inoculation on Nodulaton, N-Uptake and Crude Protein Content of Soybean [Glycine Max (L.) Merrill], At Jinka, Southern Ethiopia

Abstract

A field experiment was conducted at Jinka Agricultural Research Center to determine the effect of NP fertilizers application rate and bradyrhizobium inoculation on nodulation, N-uptake and crude prtein content of soybean [Glycine max (L.) Merrill] at Jinka under rain fed conditions in 2008. 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. Nodulation parameters, N-uptake and crude protein content of soybean were studied.  Nitrogen application significantly affected N uptake by soybean except straw N uptake. 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.

Key words: Inoculation, Nitrogen fertilizer, Phosphrous fertilizer and Soybea