Seed Carriers (page 2 of 9)
When common drills and fertilizer spreaders are used, a carrier is blended with the bulky seed. This mix then can be dispersed through the grain or fertilizer box. A good carrier adds weight, increases bulk density, and separates the seed, therefore making it flow so it can be planted with a drill or fertilizer spreader. If dry fertilizer is the carrier, its weight and hardness help keep the drill boots free of bulky seed trash. If the carrier is the proper dry fertilizer, it is also initial seedling food.

Carriers successfully used include dry granulated and pelleted fertilizer, cracked grain, dry coarse washed sand, pelleted or granulated lime, soybean meal, hard seeds such as wheat, and dry screened sawdust. All carriers must be dry. Acceptable dry fertilizer grades are the best choice because they act as a carrier and provide plant nutrition. Most of this information pertains directly to seed and fertilizer mixtures, but other carriers may be substituted for the fertilizer if it is not needed or desired. Carriers other than fertilizer have more problems.

In our region and the southeastern United States, nitrogen and phosphorus are almost always needed; therefore, 18-46-0 and complete blended grades of fertilizer such as 10-20-10, 13-13-13, 17-17-17, and 19-19-19 are good choices that are commonly available. Many other blends work well.

Grasses can respond for many years to phosphorus supplied in the grades listed above. To avoid equipment problems, use a fertilizer that has been screened to remove clods. If nitrogen and phosphorus are not needed, 0-0-60 can be used strictly as a carrier because it is the least expensive and least likely to cause seed germination impairment or seedling damage.

The fertilizer as a carrier performs better if it has irregularly shaped and sized granules and pellets and contains some dust because the combination, which the complete grades have, decreases problems with seed and fertilizer separation. Flow of the fertilizer depends on the equipment.

Grass seed germination is unaffected if the mix is made and distributed the same day or very soon thereafter, which is well documented with plains bluestem seeds (Dalrymple, 1979) and in unpublished research with crabgrass seeds. The same is true for legume seeds. In mixes fewer than six hours old, dry fertilizer had minimal effect on the legume seed inoculant (Pelinoc-Pelgel) or early seedling growth (Evers, 1986). After six hours, the fertilizers that suppressed germination the most were potassium, phosphorus, and nitrogen, in that order.