February 2016

Aspire® Alfalfa Boron Fertility


Evaluate the yield response to Aspire® with Boron (0-0-58-0.5B) compared to MOP (0-0-60).


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

  • In addition to K, alfalfa removes approximately 1.5 oz of B per ton of dry matter.

  • Granular B products can be blended with K, but low application rates of these blends often lead to undesirable distribution.

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


Locations and Crop Management:

Crop: Alfalfa (Medicago sativa)

Year: 2013–2015

Locations: 13 trials across the United States – CA, MN, NY, OH, SD, WI

004165-ASPIRE AlfalfaFertility AgriFacts k3F

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

Experimental Design: Small-plot RCBD with 4 replications.

Cropping Conditions: Trials conformed to local cropping practices and were conducted on an established stand.

K and B Sources: MOP, MOP + B blend, Aspire® + MOP (Each applied at 90 lbs K2O/ac.)

K Rate: 180 lbs K₂O/ac

B Rate: 0.75 lb B/ac as Aspire® vs. 1 lb and 2 lbs B/ac as granular borax

P Rate: As required by soil test

Application Timing: Directly following first cutting.

Application Method: Boardcast.


Boron Rate


  • Across 13 trials, Aspire® + MOP outyielded MOP alone by 0.5 ton/ac.

  • Aspire® + MOP (0.75 lb B/ac) yielded higher than the MOP + B blends applied at 1 lb and 2 lbs B/ac.

  • By combining K and B in one granule, Aspire® reduces the risk of uneven application that is common with traditional blends and improves nutrient use efficiency for maximum yields.

©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.