Guidelines for Rates and Placement of Row Fertilizer

corn, fertilizer, nitrogen, placement, potassium, row starter, starter, sulfur, urea

The principle danger to crops from excess fertilizer placed too close to the seed corn comes from excess salts. In fertilizer, the nutrients that are of primary concern are N, K₂O, and S. The combined amount of these three elements is used to evaluate the potential risks of a fertilizer rate and placement. To evaluate a particular situation, add the rate per acre of these three elements in the fertilizer, and refer to the table below.

Consult other sources when thinking of placing seed in close proximity of other crops such as soybeans, sugar beets, potatoes, small grains, etc.

Maximum “Safe” Rate of N+K₂O+S (lb./acre)
Fertilizer Location	CEC < 12	CEC > 12
With Seed	5	8
0.25” to 0.5” away from the seed	8	15
1” to 2” away from the seed	15	40
More than 2” away from the seed	20	40

Notes:

Avoid using thiosulfate and ammonia generating products, such as urea, placed with the seed.
Crops on sandy soils (CEC less than 5) will be less tolerant of fertilizer placed with, or too near the seed.
In unusually wet seasons, higher rates or closer placement of salts may be tolerated. In unusually dry seasons, the above rates and placement may cause some damage to germination.