Michigan State University Extension
Soils & Soil Management - Fertilizer - 06209708
07/10/97
Fluid Fertilizers--Liquids and Suspensions MSU Ag Facts Extension Bulletin E-933, December 1984, Revised, destroy previous editions
by R. E. Lucas and M. L. Vitosh, Department of Crop and Soil Sciences
Either dry or fluid fertilizers can be applied with the seed at planting time. However, row spacing, soil moisture conditions and type of seed greatly influence the amount that can be applied. If in doubt, do not follow the practice. Dry soil accentuates the problem of seedling injury. For wheat and other small grains planted in moist soil and in 7-inch rows, do not exceed more than 100 pounds of plant nutrients per acre (N + P2O5 + K2O). For field corn planted in 30-inch rows, the upper limit is about 15 pounds. Beans, soybeans, cucumber and melons are very sensitive to salt injury. Do not apply fertilizer on or with the seed of these crops.
Some vegetable crops, such as spinach, red beets, tomatoes and onions can benefit from a small amount of a high phosphate fertilizer placed with the seed, especially when the soil is cold. A suggested material is 10-34-0 at 5 to 10 gallons per acre for 12-inch row spacing, or 2 to 3 gallons for 36-inch row spacing. Use the lower rate for sandy soils they are likely to contain less water. Solutions such as 10-34-0 are usually diluted four or more times with water to help reduce the salt concentration and to give a more uniform application.
Fertilizers on or near the seed are more likely to benefit small seeds than large seeds, such as corn and beans. Consider the salt index value of the various solutions when applying fertilizer on the seed and use only fertilizers with a low salt index.