A soil test is the best way to determine if your soil needs phosphorus. Most of the millet is grown in the western high plains on calcareous soils. Tests have shown better results using the Olsen P test in these soils. When phosphorus is needed, the method of application is important. Phosphorus fertilizer must be banded for the root system of the young plant to make early contact with the nutrient.
Experiments often show no response to broadcast phosphorus.
The following recommendations are for banded phosphorus only. The possibility of response to potassium fertilizer is low. Table III shows the amount of potassium needed in relation to the soil test for potassium. Occasionally millet plants show striping that looks like iron deficiency but is usually a result of herbicide application. Using iron spray does not correct the symptoms.