effects of zinc application and biofertilizers on nodulation, yield and some growth characterstics of soybean

to study the effects of nano-zinc oxide and seed inoculation with brady rhizobium and plant growth promoting rhizobacteria on yield and some agronomic traits of soybean, a factorial experiment based on randomized complete block design with three replications was conducted in 2013 at the research farm of the islamic azad university, ardabil branch. treatments were foliar application of nano-zinc oxide at four levels (zero, 0.3, 0.6 and 0.9 gr/litr) and seed inoculation with brady rhizobium and plant growth promoting rhizobacteria at five levels (without inoculation as control, seed inoculation with brady rhizobium japanicum, seed inoculation with brady rhizobium r. japanicum + azosprillum lipoferum strain of, seed inoculation with brady rhizobium japanicum + psedomonas putida strain 41, seed inoculation with brady rhizobium japanicum + azosprillum lipoferum + psedomonas putida. the results showed that maximum of plant height, grain 100 weights, the number of nodules per plant and grain yield, total dry matter (530 gr/m2), crop growth rate (9.48 gr/m2.day) and relative growth rate (0.1 gr/gr.day) were obtained at foliar application of 0.9 gr/litr nano-zinc oxide + seed inoculation with rhizobium + azosprillum + psedomonas and the least of these indices were obtained at without foliar application of nano-zinc oxide + seed inoculation. it seems that using 0.9 gr/lit of nano-zinc oxide × seed inoculation with rhizobium and pgpr could increase the grain yield and some agronomic traits of soybean and can be recommended to the growers.