Irrigated Corn Silage (Code #003)
Soil Test RatingPotassium

Low K

Coast: 0-60 lbs/A

Pied: 0-100 lbs/A

Medium K

Coast: 61-150 lbs/A

Pied: 101-200 lbs/A

High K

Coast: 151-250 lbs/A

Pied: 201-350 lbs/A

Very High K

Coast: 250+ lbs/A

Pied: 350+ lbs/A

PhosphorusRecommended Pounds N-P205-K20 per Acre

Low P

Coast: 0-30 lbs/A

Pied: 0-20 lbs/A


Medium P

Coast: 31-60 lbs/A

Pied: 21-40 lbs/A


High P

Coast: 61-100 lbs/A

Pied: 41-75 lbs/A


Very High P

Coast: 100+ lbs/A

Pied: 75+ lbs/A


Coast = Coastal Plain    Pied = Piedmont, Mountain, and Limestone Valley


Recommended pH:6.0. If the pH is less than 6.0, see Lime Table C.

If soil test Mg level is low and lime is recommended, use dolomitic limestone; if soil test Mg is low and lime is not recommended, apply 25 pounds of Mg/Acre.

Coastal PlainLow: 0 - 30 lbs/acre Medium: 31 - 60 lbs/acre High: >60 lbs/acre
Piedmont Low: 0 - 60 lbs/acre Medium: 61 - 120 lbs/acre High: >120 lbs/acre
Zinc:If the Zn soil test level is low, apply 3 pounds of zinc per acre.
Other:See sulfur (S) recommendations below.

Fact Sheet:

Nitrogen can be applied from 180 to 260 pounds N per acre for expected yields of 20 to 30 tons silage yield per acre. Split the nitrogen (N) applications, applying one-fourth to one-third prior to or at planting and the remainder when the crop is 18 to 24 inches high.

Reduce the nitrogen rate by 20 to 40 pounds per acre following peanuts and soybeans, and by 80 to 100 pounds per acre following alfalfa or a legume winter cover crop that is allowed to bloom.

The applied fertilizer should contain sufficient sulfur (S) to supply 20 pounds sulfur per acre. Since sulfur is highly leachable, especially on deep sands, application of sulfur with post plant nitrogen applications may improve efficiency.