The economy of the Delmarva Peninsula of the United States is highly dependant mainly on the productivity of soybean. The low cost of soybean production is essential in enhancing the prosperity of farming communities in this region. This can be achieved by minimizing the use of expensive nitrogen fertilizers, and substituting with inexpensive and environmentally friendly rhizobia inoculants. Field studies were conducted in a Randomized Complete Block Design during the last four soybean growing seasons to examine the effect of various Bradyrhizobium japonicum strains and commercial inoculants on nodulation, growth and yield of diverse grain and forage soybean cultivars grown under the Delmarva Peninsula environmental conditions. Surface sterilized soybean seeds were coated with each of the following inoculants before sowing: TA11 NOD+, NOD+, NOD+ with Extender, NOD+ with Subtilex (Bacillus subtilis MBI600), Nitragin Cell Tech Sci, Nitragin Optimize, HiStick L N/T containing B. japonicum and B. subtilis MBI600, soybean inoculant containing strains 532c, NSI and Urbana 212 or uninoculated controls. Soybean nodulation and nitrogenase activity were determined eight weeks after planting while soybean seed and biological yields were determined at maturity. Nodulation, nitrogenase activity and soybean yield varied significantly, and this variation depended on the soybean cultivar tested and the inoculant applied. Inoculants NOD+ with Subtilex and NOD+ with Extender produced the highest nodule number and seed yield on soybean cv. AG4903. However, forage soybean cv. Tyrone indicated best nodulation and highest grain yields when inoculated with TA11NOD+ inoculant.
See more of Miscellaneous Plant Nutrition
See more of S04 Soil Fertility & Plant Nutrition
See more of The ASA-CSSA-SSSA International Annual Meetings (November 6-10, 2005)