Effect of Inoculation with Mychorrhizae, Bradyrhizobium Japonicum, and Bio-Stimulants On Growth and Yield of Soybean.

Soybean, Glycine max, is the second most important agricultural crop, after corn, in the Delmarva Peninsula of the US.  Soybean grown in the Delmarva region experiences severe drought and elevated temperatures during the growing season. Therefore, a three year 10-acre field study was conducted at the Agricultural Experimental Station of the University of Maryland Eastern Shore in Princess Anne, Maryland to examine the influence Mychorrhizae, Bradyrhizobium japonicum, and a Bio-stimulant on soybean growth and yield. Round-up Ready Pioneer variety 94M30 soybean seeds were inoculated with vesicular-arbuscular mycorrhizal (VAM) fungi, Bradyrhizobium japonicum (TA11NOD+) and Bio-stimulants (Actosol and Nitriplant SD) and evaluated four to six weeks after seed emergence for plant vigor, chlorophyll content, nodulation, and plant growth.  Data were also collected at the flowering stage to determine plant height, color, biomass, nodulation, and nodule efficiency.  At maturity, plants were mechanically harvested, and seed yield was determined. The Bio-stimulants showed early plant emergence over the control treatment, producing dark green foliage with a healthy root system (30% increased mass). The symbiotic association of the rhizobia and VAM with inclusion of actosol or Nutriplant SD increased root nodulation, plant vigor and seed yield by 10 to 20% when compared to the control. This study demonstrated the importance of utilizing a balanced selection of products to promote continued healthy sustainable soybean crop in Delmarva.