The maximum rate of seed placed nitrogen will depend on the spread of the seed. If using a press drill with one inch seed spread, the maximum rate of actual nitrogen that can be placed in contact with the seed is 10 pounds per acre. An air seeder or hoe drill will usually spread the seed a farther distance allowing for higher amounts of actual nitrogen that can be safely placed with the seed. Canola has special requirements for sulfur. The most convenient and efficient means of fertilizing canola with sulfur has been placing it with the seed.
Ammonium sulfate is a readily available form of sulfur fertilizer.
Depending on the sulfur needs of the soil, ammonium sulfate is either broadcast and incorporated or placed with the seed. Ammonium sulfate contains 21 percent nitrogen which limits how much can be placed with the seed. It is not recommended to use elemental sulfur as a seed placed sulfur source by itself. Elemental sulfur is not readily available to the plant. It needs to be broken down by soil bacteria into the form of sulfate to be taken up by the plant.