Presenter: Megan Baker
Authors: Megan Baker, Matt Yost, Earl Creech, Grant Cardon
Faculty Advisor: Matt Yost
Institution: Utah State University
There are many sources that growers utilize to determine fertilizer needs for crops such as private and public labs, crop advisors, and fertilizer dealers. In many cases, these sources provide recommendations for a specific crop that will vary greatly, and the resulting fertilizer and application rates recommended can lead to large differences in costs for the grower. Evaluating the effectiveness and economics of current fertilizer guidelines and recommendations will help growers to make better-informed decisions when it comes to choosing recommendation sources and fertilizer levels. An experiment was established in 2021 with 12 sites across the state of Utah in alfalfa, small grains, and corn to test and compare fertilizer recommendations from five labs. The recommendations tested were from two public labs (Utah State University and University of Idaho) and three private labs located in the Western United States. The macronutrient and micronutrient rates recommended by each lab were then applied in four replications at each of the 12 sites. All fertilizer products were broadcast-applied in the spring of 2021. Results from 2021 indicate that there is little to no difference statistically in crop yield between the five recommendations and the control, where no fertilizer was applied at all. Across four corn sites, there was no statistical difference in yield between treatments. In three sites with small grains, one site indicated a higher yield from two of the labs than the control. Likewise, fertilizer recommendations had no effects on alfalfa yield in 16 total harvests at five sites. While very small differences in yield were observed, the cost per acre for each treatment from the labs varied greatly. Forage quality is still being analyzed and will be utilized to calculate a return to investment for each treatment and site. These results will likely show large opportunities for improved fertilizer recommendations.