Nutrien eKonomics details potassium rebuilding steps for local growers

Nutrien eKonomics released guidance for Tennessee farmers on distinguishing between rebuilding and maintaining soil potassium levels. The company explains that the two approaches require different fertilizer strategies based on current soil test results and expected crop removal.

Rebuilding soil potassium involves applying fertilizer in excess of what the harvested crop removes. Growers should adopt this method when soil samples indicate potassium levels are below the established critical value for the state. These low levels often appear in the very low or low categories on soil tests. Maintaining potassium levels requires applying only as much fertilizer as the crop removes from the field. This maintenance strategy applies when soil values are already above the critical threshold.

Farmers need two pieces of information to choose the correct approach. They must have a recent soil test and know the nutrient removal values for their expected harvest. University recommendations help determine how much potassium is needed to raise soil levels back above the critical value.

Experts note that rebuilding soil fertility does not require applying all necessary nutrients in a single season. Many growers use a four to five year plan to spread costs and logistics over time. This approach creates a slow ramp rather than a single large application. Farmers should divide the total amount needed to reach the critical value across the chosen number of years.

Once soil potassium levels are above the critical value, growers shift to maintenance mode. In this phase, the goal is to keep soil levels stable. Farmers can calculate the exact amount of fertilizer needed by using yield numbers and a crop nutrient removal calculator. This tool determines the pounds per acre of potassium oxide removed from the field. The calculated amount is then replaced in subsequent fertilizer applications.

The guidance emphasizes that soil potassium management is not always a simple replacement of crop removal. Farmers must assess whether they are in a rebuilding or maintenance phase to ensure long term fertility. Nutrien eKonomics states that knowing the specific shortfall in soil potassium is the first step in planning the appropriate fertilizer program.