PROMOTING ACCESS TO AFRICAN RESEARCH

Ethiopian Journal of Agricultural Sciences

Log in or Register to get access to full text downloads.

Remember me or Register



Effect of inoculating Bradyrhizobium on phosphorus use efficiency and nutrient uptake of soybean in calcareous soil, central Rift Valley, Ethiopia

Tesfaye Fituma, Tamado Tana, Anteneh Argaw

Abstract


At a soil pH value of above 7.0, inorganic phosphorus (P) is highly susceptible to precipitation as insoluble form that is unavailable to plants. Hence, a field experiment was conducted at Metehara Sugar Estate under irrigation during the 2014/15 cropping season to evaluate the effect of inoculating Bradyrhizobium on P uptake and P use efficiency of soybean intercropped with sugarcane. The treatments consisted of three levels of inoculation (Legume fix, SB6B1 and uninoculated) and four rates of P (0, 10, 20 and 30 kg Pha-1). The experiment was laid out in a randomized complete block design (RCBD) in a factorial arrangement and replicated three times. Analysis of the data indicated that Bradyrhizobium inoculation significantly increased plant N concentration and P uptake compared to the uninoculated treatment. The effect of P rates and its interaction with inoculation was not significant on N concentration and P uptake, but significantly increased total P uptake at the application of 30 kg Pha-1. Phosphorus use efficiency indices were improved in response to inoculating the crop with Bradyrhizobium. The highest AE (13.6 kg kg-1), PRE (31.8%) and PUE (10.6 kg kg-1) were obtained by SB6B1 inoculation and the highest PE (117.2 kg kg-1) and APE (161.7 kg kg-1) were obtained by Legumefix inoculation all at 10 kg P ha-1except PE which recorded the highest at 30 kg P ha-1.Thus, it can be concluded that SB6B1 isolate can be used as the best inoculant followed by Legumefix isolate with 10 kg P ha-1of P fertilizer. However, strategies for increasing P use efficiency by adopting best management practices like co-inoculation of phosphate solubilizing microorganism or mycorrhiza with these Bradyrhizobium inoculants should be adopted to enhance P use efficiencies.




AJOL African Journals Online