What are inoculants?
Inoculants are beneficial bacteria that work to form the nitrogen-rich nodules found on legume roots. These bacteria, specifically rhizobacteria, do the work of taking nitrogen from the air and “fix” or concentrate it in root nodules which then slough off, adding nitrogen to the soil in a form plants can absorb. However, other naturally occurring bacteria compete with nitrogen-fixing rhizobacteria for a home on legume roots. That is why it is important to inoculate your seeds before planting, to ensure a high level of viable rhizobacteria when the seed germinates.
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. Use on raw legume seed and make sure you select the proper strain for that seed. If the seed says "Nitrocoated" it already has the inoculant coated on the seed and you do not need to inoculate. Many small seeds, such as clovers, are sold as nitrocoated, so all you need to do it plant them.
When should I use inoculants?
Use inoculant every time you plant any legume, even if you’ve inoculated that soil area before. Inoculants are live bacteria, so be sure to use it prior to the expiration date on the package. Use new inoculant when in doubt.
How do I inoculate seeds?
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 and make sure the seeds are not sitting in the sun. The seeds will turn black when properly covered.