Using Fertilizer Spreaders (page 7 of 9)
The seed-fertilizer mixtures can be planted with essentially any dry fertilizer spreader, including old drill-box-type fertilizer spreaders that have metal agitators in the hopper (figure 8): Ezy-Flow, Judson, IHC, and John Deere are among those who sold them. Models 10 feet wide and narrower are available from Gandy Equipment Company (528 Gandria Rd., Owatonna, MN 55060, [507] 451-5430; figure 9). Any equipment dealer should be able to obtain spreaders from Gandy.

Figure 8. An old model of a drill box fertilizer spreader being used to plant a bulky seed-fertilizer mixture

The rotary spreaders (spinner spreaders) are available almost universally. These machines easily spread the seed mixture in about 20- to 30-foot-wide patterns. However, the dry fertilizer will be thrown two to three times farther than lighter seed. To reduce this effect, set the fertilizer-rate gate to about one-third to one-half the usual rate, e.g., 30 to 50 pounds per acre versus 100, and take one-third to one-half the normal swath width, e.g., 20 to 30 feet per swath versus 60. With this procedure, the seed pattern overlaps somewhat and the volume of fertilizer is doubled to get the total rate per acre. The actual swath or pattern depends on the seed and fertilizer spreader and the rates it can apply. Many commercial-sized fertilizer spreaders will not apply the low rates listed and higher rates must be used. Check the seed pattern and adjust the machinery accordingly for full seed coverage. Spinner spreaders never provide a perfectly uniform spread.

Where many cash crops are grown, airflow fertilizer spreaders are often available and are excellent for spreading seed-fertilizer mixtures (figure 10). They provide a uniform wide pattern and are often the most precise broadcasters available commercially, and the operator can quickly cover many acres.

Always spread the mixture on calm days or those with a gentle breeze and take advantage of crosswinds so the patterns will overlap better.

Be cautious about mixing big batches and spreading over large areas: the mix may separate some, and you may need to remix the last of it with a scoop.

Figure 9. A Gandy Co. drill-box-type seed-fertilizer spreader in operation (photograph courtesy of Gandy Co.)

Figure 10. A modern airflow fertilizer spreader being used to plant a bulky seed-fertilizer mixture on a good seedbed