February 2016

Aspire® Soybean Boron Fertility


Evaluate the yield response of Aspire® with Boron (0-0-58-0.5B) compared to MOP (0-0-60). Compare the yield response of Aspire® to a MOP + Boron (B) blend applied at multiple application rates.


  • MOP is commonly used as a potassium (K) source in soybean production.

  • Micronutrients such as B are essential for plant growth and are often overlooked for balanced crop nutrition.

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

  • Aspire® is the first-of-its-kind micronutrientenhanced potash fertilizer. Formed using Nutriform® technology, Aspire® combines K and B in each granule to help achieve uniform nutrient distribution


Locations and Crop Management: Corn (Zea mays)

Crop: Soybean (Glycine max)

Years: 2013-2015

Locations: 31 trials across the United States – AL,AR, GA, IA, IL, MN, MO, MS, NC, OH, SC, TN, WI

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 balanced for fall and spring treatments separately.

P Rate: As required by soil test

K Rate: 60 lbs K₂O/ac

B Rate: 0, 0.5, 1, 2 and 4 lbs B/ac

Application Timing and Method: Preplant broadcast


MOP+B_Aspire Yield


  • Aspire® increased yield by 1.3 bu/ac (2.3%) over MOP.

  • A preplant application of Aspire® at 0.5 lbs B/ac outyielded the MOP + B blend applied at 0.5, 1, 2 and 4 lbs B/ac.

  • Increasing the rate of granular B applied increased toxicity symptoms and decreased plant stands, which resulted in lower yields.

  • The higher yield with Aspire® compared to MOP + granular B demonstrates the advantages of uniform nutrient distribution with a micronutrient-enhanced potash fertilizer.

©2020 The Mosaic Company. All rights reserved. AgriFacts, MicroEssentials, SZ, Fusion, 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.