Fall Harvest Observations by Frank Flis

While harvesting this year’s crop, staying aware of abnormalities is always prudent.  However, this season’s weather patterns may throw you a few curves, especially when looking for nutrient challenges. During the extended hot and dry periods the crop struggled to get necessary nutrients from the soil. With the goal of producing a seed the plant begins to cannibalize itself.

Translocating nutrients (those that move within the plant) like Nitrogen (N), Potassium (K), and Sulfur (S) will tend to move from within the plant to the growing point of the grain or seed. Under this season’s extreme deficiency, symptoms will appear on the plant–especially flaring on the lower leaves which indicate movement of N and K. Pale upper leaves may indicate S movement through the plant. During periods of minimum rainfall and low production, N is not mineralized in the soil leaving the plant to act on itself.  Late season rain arrived in many areas and N has been activated resulting in a new green up with signs of deficiency on lower 4 leaves. To further complicate the evaluation process, using Stalk Nitrate Tests (CSNT’s) will likely show excess N in the stalks making plans for next season more complicated.

As always, records of weather, nutrients applied, yield data, and fresh soil tests will help with that planning process for upcoming planting season. Unused nutrients from this season, especially K and N, make gathering more information a priority. The K will move little and there is potential of up to 50% of the N still in the soil both from applied N and normal unmineralized soil N. Capturing
some of these nutrients with a cover crop may be beneficial.

Good soil tests will be very important this fall to determine the leftovers and developing a strategy for 2017 growing season. Compiling yield data, field observations, soil information, and fall field adjustments (lime, cover crop) add to that planning process