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

Potassium is attracted to the negatives charges on soil particles that make up the cation exchange complex.  Thus loss from agricultural fields is rarely an economic problem, with the possible exception of sandy soils  with very low cation exchange capacity (CEC) values.  Unused potassium fertilizer from one year can be used the next.

Potassium loss from agricultural fields is not an environmental concern.

Yield response to K in Missouri

Field-scale response to K in Missouri

K in Missouri subsoils

Variable-rate K:  economic analysis tool

K placement:  economic analysis tool

Grain K removal