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Topics : Successful Forage Establishment : Inoculation of Legumes for Maximum Nitrogen Fixation

Inoculation of Legumes for Maximum Nitrogen Fixation

Additional inoculation information via the Forage Information System (FIS)


Emergency Inoculation

If the lack of effective nodulation on a newly seeded crop is known or feared, then inoculant can be applied to the crop in the field. Nodulation deficiencies can be corrected, although not entirely overcome, by salvage (emergency) inoculation up to four weeks after seedling emergence. The grower may use one of several techniques and expect equal results. Rate of application of actual inoculant should be in the range of 1 1/4 to 1 3/4 pounds per acre regardless of the application method. The methods are:

  1. Drilled application of a granular peat-based inoculant 1 inch deep.
  2. Drilled application of inoculated sand. In this case, you need to inoculate sand just as you would seed, and to use a sticker. Inoculate an amount of sand for an application rate of between 60 and 90 pounds per acre and drill 1 inch deep.
  3. Sprayed application of a water-inoculum suspension. Prepare the treatment by combining powdered peat-base inoculant with about a quart of water and shaking to ensure adequate saturation. After seiving to remove large peat particles, add this suspension to a water-filled sprayer tank. Remove nozzle screens and spray uniformly over soil surface. Application by this method should be made only on a cloudy day just before rain is expected or irrigation is scheduled.

If the crop was fall-seeded and if cold weather has set in, then salvage inoculation should be delayed until early spring when the soil is warmer.