Four Years and Counting: An Update on Seasonal Soil Testing Variation.

Soil testing is the foundation of nutrient management. However, the results from the location vary according to the time of year that fields were sampled. This can lead to different fertilizer or lime recommendations, with very different costs to the producer. This presents several issues for Extension programming. To provide background for the outreach, eight georeferenced locations have been sampled monthly on Mississippi State University research farms since April 2011. Standard analytical procedures for soil moisture, phosphorus (P), potassium (K), pH, and lime requirement for row crop samples of the MSU Extension Service Soil Testing Laboratory are used. There is a biannual cycle for P and K results. Soil pH and lime requirements vary with soil moisture conditions.