EFFECT OF PHOSPHORUS, MOLYBDENUM AND BRAD YRHIZOBJUM INOCULANTS ON NODULATION, GROWTH AND YiELD OF SOYBEAN (Glycine max L. Merrill)

Abstract

An experiment was conducted at the experimental field of the Department of Soil Science, Bangladesh Agricultural University. Myniensingh during Januan' to May 2003 to study the effect of added P. Mo and I3radyrhizobiurn inoculant on nodulation, yield and yield contributing characters of two soybean cultivaj- s, Pb-I and 0-2. The treatments were: Control, Inoculurn, P+Jnoculum, Mo+Inoculum, P+Mo+Inoculum. The rates of P, Mo and Bmdvrhizobium inoculant were 40 kg P ha 1 . 1 kg Mo ha1 and 15 g inoculant kg' seed, respectively. TSP was used as a source of!' and sodium molybdate as that of Mo. Basal application of 40 kg K had, 15kg S ha 1 and 2 kg Zn h ad was made to all plots for crop raising. The variety was placed in the main plots and the fertilizer and J3radyrliizobiutn inoculant were placed in the subplots. At 75 EMS, 10 plants were uprooted from each plot for recording data on nodulation and growth characteristics. The crop was harvested at maturity after 120 DAS. Between varieties, the 0-2 showed higher nodulation, number of pods and seeds plant 1 compared to Pb-I variety. On the other hand, variety Pb-I gave significantly higher 100-seed weight, seed and stover yields comparcd to the 0-2. Bra dyrhizobi mu inoculation significantly increased nodulation, number of pods and seeds plan(' and finally seed and stover yields of' soybean. The combined application of P and Mo with Bradyr/2izobiwn inoculation further increased the nodulacion and yield of soybean varieties. Bradyrhizobium inoculation was found essential for soybean cultivation at BAU Farm and an application of P and Mo further increased the yield.