Nutrient Uptakes by Corn
By Randy Simonson, Technical Services Manager
An average corn crop will use 240 lbs of nitrogen/acre, 100 lbs of phosphorus/acre and 240 lbs of potassium/acre
through the crop season. The amount and percent the corn uses varies with different times during its growth.
The corn crop actually uses a higher amount and percentage of nitrogen and potassium during the seedling
stage than it uses phosphorus. Yet we use starters with a high concentration of phosphorus in them. This is
because phosphorus is less available when soils are cold and wet. Interestingly, recent research in the northeast
on soils with high phosphorus levels has shown more benefits using a starter without phosphorus but with nitrogen, potassium and sulfur. But remember, this is on high phosphorus soils.
The greatest percentage of potassium is used during the rapid growth stage whereas most nitrogen and
phosphorus are used during silking. Nutrient requirements progressively decrease after silking.
Nutrient Uptakes by Corn at Different Growth Stages (lbs./acre)
|Seedling|| Rapid Growth||Silking||Grain Fill||Maturity||Total|
|Nitrogen||19||84 ||75|| 48||14 ||240
|Phosphorus || 4||27||36||25||8||100
|Potassium||22 || 104 ||72||36 || 6||240