For soybeans being planted into a new field, three times the normal rate of inoculant is recommended. A good way to achieve this is to moisten the seed with liquid inoculant applied at the normal rate, then mix seed with twice the normal rate of peat-based inoculant. Forage seed may be purchased already inoculated. The pelleted type of preinoculated seed is generally preferred on the basis of research that shows that bacteria live longer on the pelleted seed and that this type of preinoculated seed results in formation of a greater number of root nodules. Preinoculated seed should be handled in the same way as packaged inoculum.
Several precautions can ensure better results.
Check for an expiration date on the seed-bag tag, store and transport the seed out of direct sunlight and heat, and plant the seed as soon as possible. If you believe that bacteria may have died, then reinoculate the seed. In Pennsylvania, Mo is generally present in soils in sufficient quantity, but its availability is affected greatly by the soil pH. Soil into which a legume is being planted should be limed to raise the pH to between 6.5 and 7.0. Some inoculants or preinoculated seed maybe sold with combinations of Mo and or a fungicide. These additional treatments tend to reduce the number of live Rhizobia and generally are not recommended.