Legumes work in harmony with a group of bacteria (rhizobacteria) that live symbiotically on their roots. These bacteria do the work of taking gaseous nitrogen from the air and “fix” or concentrate it in pink root nodules which then slough off, adding nitrogen to the soil in a form plants can absorb.
Properly inoculated legumes can generate up to 300 lbs of useable protein-based nitrogen per acre. Inoculating with rhizobacteria also significantly increases top and root growth in legumes, thus increasing organic matter, soil aeration, and soil stabilization.
Rhizobacteria exist naturally in the soil, but not in sufficient amounts to maximize nitrogen fixation. Other naturally occurring bacteria compete with nitrogen-fixing rhizobacteria for a home on legume roots. It is important to inoculate (coat the seed) to ensure a high level of viable rhizobacteria when the seed germinates.
Many of the legumes we provide are preinoculated with the correct rhizobacteria and a protective coating. For “raw” or uninoculated legume seed, we highly recommend you purchase the appropriate inoculant. Different strains of rhizobacteria work only on specific seeds.
Use inoculant every time you plant any legume, even if you’ve inoculated that soil area before. Because the bacteria is alive, it should be used prior to the expiration date on the package. Use new inoculant when in doubt.
Just prior to sowing, put the seed in a bucket or barrel and moisten it a little with water so that the inoculant will stick to it. Another method is to use milk & molasses as a sticking agent (as well as to provide food for the bacteria). Sprinkle the inoculant onto the seed and mix thoroughly until the seed is well coated. The seed will turn black when properly covered. You cannot use too much inoculant. Don’t leave the inoculated seed in the sun.