Wednesday, March 31, 2021

Springtime fertilizing

     Every Spring I fertilize my pecan orchard and today was the day I accomplished that task. Two factors go into my decision for timing the Spring fertilizer application. The first is bud development and the second is field conditions.  Fertilizer nutrients are most rapidly taken up by pecan roots during the Spring flush of root growth. When I see the buds of pecan branches start to swell and out scales begin to split open (photo above), I know root growth has begun.

    The second factor is field conditions. The ground must be dry enough to support the weigh of 4 tons of fertilizer being hauled in a spreader over the field. I also look at long term weather predictions to increase my chances of not letting flood waters leach away all my applied nutrients.

    This spring I applied 200 lbs/acre of urea fertilizer (92 lbs/acre of nitrogen). I also applied 200 lbs/acre of a product called K-Mag. K-Mag is composed of the naturally occurring mineral,  sulfate of potash-magnesia. K-Mag contains 22% potassium, 22% sulfur, and 11% magnesium. In the past, I always used straight potash with my urea in the spring. However, since liming the orchard a few weeks ago, I knew the additional calcium (lime)  I added to the soil can inhibit magnesium uptake. By using K-Mag, I could add both needed potassium and increase soil magnesium levels.

   This summer I'll take leaf samples from my trees and send them off for analysis. By mid summer, I'll have the data to see how well these soil amendments preformed.