February 2021

Aspire® Soybean Fall vs Spring Broadcast


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


  • Muriate of Potash (MOP) is a common potassium (K) fertilizer used in soybean production.

  • Micronutrients such as boron (B) are essential for plant growth and are often overlooked in efforts to provide balanced crop nutrition.

  • Granular B products can be blended with MOP, but application of these blends leads to undesirable B distribution.

  • Aspire is a premium K fertilizer that uses Nutriform® technology to combine potash along with two forms of B (fast and slow release) in every granule. This combination delivers B uniformly for uptake throughout the growing season, and provides a flexible application window compared to other B sources.


Crop: Soybean (Glycine max)

Years: 2018-2020

Locations: 15 trials across the following states - AR, IA, IL, MN, MO, MS, NC, NE, OH, SC, TN, WI

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

Experimental Design: Small-plot RCBD with 4 replications.

Cropping Conditions: All trials conformed to local cropping practices.


Treatment (Trmnt) / Rates / Timing:

  1. P Rate: As required by soil test

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

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

  4. Application Timing: Fall or Spring

Application Method: Broadcast Incorporated


Aspire® Soybean Fall vs Spring Broadcast - Results


  • Soybean yield increased with the addition of B.

  • Across 15 site-years, Aspire increased soybean yield 1.9 bu/ac over MOP and 1.1 bu/ac over MOP + Granular B averaged across fall and spring applications.

  • Aspire with two forms of B demonstrates the value of uniform nutrient distribution and season-long B availability for a flexible application window and greater soybean yields.

©2021 The Mosaic Company. All rights reserved. AgriFacts, Aspire and Nutriform are registered trademarks of The Mosaic Company.

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. For more information, go to AspireBoron.com.