February 2018

Aspire® Corn - Fall vs. Spring Broadcast


Evaluate the yield response of corn to Aspire® (0-0-58-0.5B), MOP (0-0-60) and MOP + Granular B (0-0-0-14.3B) blend in fall vs. spring applications.


  • MOP is commonly used as a potassium (K) source in corn production with applications made in both spring and fall, depending on region and seasonal workload.

  • Micronutrients such as boron (B) are essential for plant growth, yet often overlooked in balanced crop nutrition.

  • Granular B products can be blended with K, but results in an uneven distribution of B. Additionally, boron is mobile in the soil and is prone to leaching.

  • Aspire® is a premium potash that includes two forms of boron to deliver season-long availability and a more flexible application window, regardless of application timing.


Crop: Corn (Zea mays)

Years: 2016–2017

Data Source: Field studies conducted by third-party, independent researchers.

Experimental Design: Small-plot RCBD with 4 replications.

Cropping Conditions:

N Rate: Recommended nitrogen (N) was applied in spring and balanced across all treatments.

K Rate: 60 lbs K₂O/ac applied as MOP or Aspire®

P Rate: 80 lbs P₂O₅/ac applied as MAP and balanced across the entire trial

B Rate: 0.5 lb B/ac applied as Granular B or Aspire®

Application Timing: Fall vs. spring preplant

Application Method: Broadcast incorporated


Fall Corn Yield
Spring Corn Yield


  • Corn yields increased with the addition of potassium and boron.

  • Highest corn yields were achieved with Aspire® treatments in both fall and spring application timings.

  • Fall: Aspire® yields were +4.8 bu/ac over MOP and +2.2 bu/ac over a MOP + Granular B blend.

  • Spring: Aspire® demonstrated a +5.3 bu/ac yield advantage over MOP and a +1.9 bu/ac increase over a MOP + Granular B blend.

  • Peak yields achieved with Aspire® demonstrate the benefits of boron in corn production and the advantages of Nutriform® technology, which provide uniform nutrient distribution compared to a MOP + Granular B blend.

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Individual results may vary, and performance may vary from location to location and from year to year. This result may not be an indicator of results you may obtain as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible.

WARNING: Contains boron. Use of boron may result in crop injury. DO NOT place this product in direct contact with the seed.