Need for Fall Fertilizer

With the latest USDA forecast indicating a USA corn crop size of 14.0 billion bushel and soybean production at 3.26 billion bushel for 2013, these production levels for 2013 were not grown in the most favorable weather conditions.

There are two experiments at our Agronology 10 Research Center at Walcott, IA, which clearly demonstrates the need and value for sound ongoing fertility management practices.

Experiments

The first experiment “Critical Considerations” is a summary for the top 24 yielding corn plots in 2013.

The average yield for this grouping in 2013 was 233.7 bu/a.

Applied fertility facts for this group:

• Fall dribble band corn fertility program.
  • 23 of 24 had P&K applied in Fall 2012.
    • 16 of 23 plots were fertilized with 29-55-85.
    • 3 of 23 plots were fertilized with 29-50-75.
    • 2 of 23 plots were fertilized with 29-60-95.
    • 2 of 23 plots were fertilized with 29-45-65.
  • 21 of 23 plots were fertilized with sulfur (10-20 lbs/a) and zinc (0.428-0.749 lbs/a).
  • 18 of 23 plots also had boron added as the third micro-nutrient (0.2-.5 lbs/a).

In our second experiment, “Fertility Maintenance,” a corn fertility program of either 29-50-75-15s-.535Zn-.3B (200 bu. program) or 29-55-85-15s-.642Zn-.4B (220 bu. program) was dribble band in the fall 2012 for the 2013 corn crop.

A review of the proceeding year’s soybean fertility was interesting in how it influences the 2013 corn yield (Table 1).

Table 1: Influence of Soybean Fertility on 2013 Corn Yield