Phosphorus

Phosphorus (P) is a crucial nutrient for plant growth. It is one of the three primary nutrients (along with nitrogen and potassium) because natural levels of phosphorus in soil often limit plant growth.

Phosphorus binds tightly to soil and loss from agricultural fields is rarely an economic problem. Unused phosphorus fertilizer from one year can be used the next. A network of experiments across Missouri has shown that there is little or no yield response to P fertilizer when previous fertilizer management has maintained soil test levels at the target levels recommended by the University of Missouri.

When phosphorus is lost from fields, it is mainly by erosion. Relatively small amounts of phosphorus that are lost this way can have negative impacts on water bodies, where the phosphorus can greatly increase growth of aquatic plants.