FAQ – Frequently Asked Questions

Why are Yellow Jacket seeds better than just any farm-inoculated/pre-inoculated seeds?
The Rhizobia in Yellow Jacket seeds are embedded in a polymer matrix around the seed. Extra preservatives and nutrients have been added to this matrix to increase shelf life and prevent the Rhizobia from stress. For that reason the number of Rhizobia on Yellow Jacket seeds is much higher than on seeds that have simply been farm-inoculated/pre-inoculated.


Why is a high number of Rhizobia per seed so important?
There is a strong relationship between the number of Rhizobia on the seeds before sowing and nodulation + nitrogen fixing in the alfalfa plants. A high number of Rhizobia will lead to more active nodules and more nitrogen fixing.


What is the optimal sowing rate for Yellow Jacket seeds?
Barenbrug recommends using a sowing rate of a minimum of 25 kg/ha. This is the same as the sowing rate recommended for bare seeds.


Why do Yellow Jacket seeds establish better?
After sowing, the coated seeds are heavier and have better soil contact. The seed coat attracts and holds moisture, so the seed germinates and establishes better than bare seeds. Yellow Jacket contains a nutrient booster, which stimulates the seedling and the activity of the Rhizobia. Finally, lime (CaCO3) from the coat lowers the pH around the roots, which results in better plant establishment and production.


Why is it always wise to use Rhizobia?
Rhizobium bacteria are essential for supplying nitrogen to lucerne. With enough Rhizobia in the soil, there is no longer any need for nitrogen fertilization. If there is no history of lucerne in the soil, it will not contain any Rhizobia naturally. If lucerne has been growing in the soil in the recent past, Rhizobia may still be active, but in the case of crop rotations the population decreases rapidly. Using inoculated seeds will bring a high number of active Rhizobia to the soil. In addition, the Rhizobia in Yellow Jacket – Rhizobium coated seeds are very close to the seeds, maximizing effectiveness.