Wheat planting is quickly approaching in parts of Kansas, so now is the time to get your soil sampling done to have good information on which to base your fertilizer inputs, writes Dorivar Ruiz Diaz, Nutrient Management Specialist at Kansas State University. This is particularly important since we continue to see very tight margins for wheat, and efficiency with focus on the most important variables in production will be critical.
Which Nutrients Should Be Tested?
The most important tests and nutrients to focus on this year depends in part on where you are located, the choices you make when applying N, and your tillage system. The nutrients for which wheat is most likely to show responses statewide are nitrogen (N) and phosphorus (P). Wheat is the most P-responsive crop we grow in Kansas, and while P removal with wheat may be less than with corn or soybeans, the relative yield response is often the highest. Therefore, knowledge of P soil test levels and fertilizer needs will be valuable. In addition, low soil pH is becoming a problem, especially fields with a history of high rates of N application and relatively low cation exchange capacity.
In addition to the “Big 3” (pH, N, and P), potassium (K) deficiency in wheat can also be found in some areas of southeast and south central Kansas. Wheat is generally less prone to K deficiency than many of the rotation crops commonly grown, such as corn, soybeans or grain sorghum. Generally, the focus of a K fertilization program is with the rotation crops, and meeting the higher K needs of corn and soybeans minimizes the chance of a K deficiency in wheat.
