End of October Reflections

If you are farming in the droughty area like we experienced at the Agronology 10 Research Center in Walcott, IA in 2013, we observed roughly a 25 bu/a corn difference in 2013 from 2012.

In 2013, our source of P and K for corn experiment averaged 193 bu/a for those 48 plots while in 2012, the yield for those 48 plots was 217 bu/a. The previous crop in both instances was soybeans. However, our 2013 corn on corn overall yields of 179 bu/a are slightly above our 2012 yield of 175 bu/a.


Now, for a couple of experiments, the results showed that the complete N-P-K + micros in a dribble band were the way to go.

A basic corn fertility program of either 29-50-75-15s-.535zn-.3B or 29-55-85-15s-.642zn-.4B was dribble banded in Fall 2012 for the 2013 corn crop and the influence of the previous year’s soybean fertility program is shown in Table 1.

Table 1: Influence of Soybean Fertility on 2013 Corn Yields
Dribble Band Soybean Fertility                                Corn Yield (Bu/A)

17-40-80                                                                          189.7

17-40-80-1.3Mn                                                               190.1

17-40-80-10s                                                                   195.5
17-40-80-10s-1.3Mn                                                        200.0_________________


From the Critical Consideration data for the top 24 yields which yielded 233.7 bu/a, a review for the applied fertilizer can be seen.

  • For the fall dribble band: corn fertility.
    • 23 of the 24 plots had P&K applied in Fall 2012.
      • 2 of 23 plots had 29-45-65 applied.
      • 3 of 23 plots had 29-50-75 applied.
      • 16 of 23 plots had 29-55-85 applied.
      • 2 of 23 plots had 29-60-95 applied.
      • 21 of the 23 plots which had N-P-K applied also had sulfur and zinc applied.
    • 18 of the 23 plots which had N-P-K applied also had sulfur, zinc and boron applied.
    • For the fall dribble band: soybean fertility.
      • 23 of 24 plots had N-P-K applied for the prior year’s soybean with a fertility of 17-40-80 or greater.
      • 16 of 24 plots had 10 lbs. sulfur applied.
      • 13 of 20 soybean fertilized plots had a manganese application.