Effects Of Co-inoculating Soil Yeast (Saccharomyces Cerevisiae And Saccharomyces Exiguus)with Bacteria (Bradyrhizobium Japonicum)on Growth,Nitrogen Fixation And Yield Of Glycine Max(L.)

Availability of plant macronutrients?nitrogen,phosphorus and potassium?in the soil is one of the main factors influencing crop productivity.Availability and forms of these mineral elements greatly varies with soil type.Research has shown that successful supplementation of soil nutrition to plants can be optimised by providing appropriate microbial symbionts for the plants.Furthermore,soil yeast is capable of solubilising unavailable phosphorus and iron as well as producing plant growth hormones which are of use in the processes of plant growth and bacterial activity.The aim of this study was to determine the effect of co-inoculating plant growth promoting bacteria?PGPB?Bradyrhizobium japonicum and plant growth promoting soil yeast Saccharomyces cerevisiae and Saccharomyces exiguus on Soybean?Glycine max L.Merr?growth and yield with particular attention on how the soil yeast will affect bacterial atmospheric nitrogen fixation rate and nodulation.The soybean cultivar Taiwan 292 was grown in pot experiments with 6 treatments[B.japonicum?T1?,S.cerevisiae?T2?,S.exiguus?T3?,B.japonicum+S cerevisiae?T4?,B.japonicum+S.exiguus?T5?and the witness?T6?],replicated 4 times.Co-inoculation with Bradyrhizobium japonicum did not have a significant effect on the parameters evaluated.Results revealed that co-inoculation B.japonicum and S.cerevisiae or B.japonicum and S.exiguus on soybean led to improved seedling root and shoot growth,dry matter during the initial growth stages.It also led to an improved nodule number plant^-1,nodule dry weight,root and shoot growth,atmospheric nitrogen fixation,improved nutrient supply and seed yield of soybean as compared to sole bacterial inoculated and un-inoculated treatment.Sole bacterial inoculation and sole yeast inoculation did not have a significant improvement on the initial plant growth and development,leaf chlorophyll content,nodule number,nodule dry weight,atmospheric nitrogen fixation,plant dry weight,plant phosphorus,nitrogen content and protein content as compared to dual inoculation.Based on these results,it indicated that,dual application of soil yeasts and nitrifying bacteria enhances soybean biochemical and physiological activities leading to an improved growth and productivity.A recommendation is made to co-inoculate soil yeast and nitrifying bacteria as bio fertilizer for improved soybean productivity.