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.

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.

Yield response to P in Missouri

Field-scale response to P in Missouri

P in Missouri subsoils

Variable-rate P:  economic analysis tool

P placement:  economic analysis tool

Grain P removal