The P guidelines for corn in New York State are based on soil testing and crop yield response studies. The Cornell P guidelines for corn (Y-axis), below, make the link between the soil test P level (X-axis) and the likelihood of no crop yield response from additional P fertilizer (very low, medium, high, and very high).
Try making a P recommendation for corn, below.
Click to the next page to learn how to meet the crop P guidelines with fertilizer and manure.