By Scott Carlson
Pre-plant Nitrogen fertilizer will depend mostly on what was just harvested from the field this season. Below are recommended N amounts:
- Cotton – 35 to 40 lbs/ac
- Corn or Fallow – 30 to 35 lbs/ac
- Soybeans – 15 to 20 lbs/ac
- Peanuts – 0 to 15 lbs/ac
Tillers produced in the fall generally produce the most grain per unit area. It is important not to over-fertilize with N in the fall as it may cause excessive growth and result in winter injury.
Total N will be between 100 and 130 pounds per acre depending on many factors. Too much and it will fall over. We need most of it in late January and February as one or two side dressings – depending on tillering level by end of January.
Timing of N fertilization should be based on the pattern of uptake by the crop. Demand for N is relatively low in the fall but increases rapidly in the spring just prior to stem elongation. Therefore, make the fall applications of nitrogen at planting, and the remaining N prior to stem elongation. Use the lower rate of fall applied nitrogen at planting on heavier-textured soils and the higher rate on sandy soils.
Other nutrients should be applied according to a soil test pre-plant.
Since 65% of the total P uptake and 90% of the total K uptake occurs before the boot stage, these nutrients should be applied according to soil test before planting and thoroughly incorporated into the rooting zone.
Source : uga.edu