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On-Farm Trial Research Data

Since each farm presents a unique set of challenges, on-farm research has emerged as a valuable way for farmers to collect customizable data specific to their operations. Results from 2018 on-farm trials across the state of Minnesota are now available for farmers to use as part of their own decision-making process.

Beginning in 2017, the Agriculture Fertilizer Research and Education Council (AFREC) funded Minnesota Crop Production Retailers (MCPR) and Matt Wiebers, an independent agronomist, to conduct on-farm trials in corn across the state of Minnesota. Utilizing precision ag data that many farmers are already recording, the trials were integrated into each farmer’s existing fertility plan and required minimal extra work and time for the farmer and his/her advisor.

“On-farm trials allow farmers to test new products and production methods within their own operation,” explains Wiebers.  “One of the biggest advantages to on-farm research is the ability to conduct research across in many different locations to study different soil types, weather patterns, and management practices. Properly designed on-farm trials can provide statistically significant results and data to help farmers and policy makers improve their decisions based on data.”


On-Farm Trials Not Limited to Typical Research Locations

For the 2018 trials, 48 sites were established across the state’s five nitrogen best management practice (BMP) regions. These regions are defined primarily based on soil type and climate. (For more information about BMP regions, check out University of Minnesota Extension’s Best Management Practices for Nitrogen Use in Minnesota, published in 2008.)

The trial locations were distributed across the BMP Regions as follows:

  • Northeastern – 7 locations
  • Northwestern – 1 location
  • South Central – 5 locations
  • Southeastern – 16 locations
  • Southwestern and West Central – 18 locations

Corn was selected as the crop evaluated due to the amount of fertilizer required, and that corn is one of the primary crops grown in the state. The following data was collected from each of the sites:

  • As-applied data from the application of nitrogen by the retailer or farmer
  • Yield monitor data from the combine
  • Aerial photography collected in-season
  • Cropping history such as tillage practices and rotation
  • Residual soil test nitrate after harvest (on 10 of the trial sites)

In conjunction to the data listed above, Wiebers also gathered the following data from public sources:

  • Soil type and texture
  • Precipitation
  • Slope

These metrics allow evaluation of the data against other factors that were present at each trial location that could account for different trends and insights.

Below are the overall findings. Initial results are show in this article. More detailed analysis will be available in March 2020.


Nitrogen Applied Rate

2018 Average Yield Results (bu./acre) by BMP Region

Lower Rate N (Bu/Acre) Avg. Lower N Rate Applied (lbs.) Farmer Rate N (Bu/Acre) Avg. Farmer N Rate Applied (lbs.) Increased Rate N (Bu/Acre) Avg. Increased N Rate Applied (lbs.)
Northeast (7 trials) 204.2 119 209.1 146 212.2 166
Northwest (1 trial) 196.2 100 200.5 130 NA NA
Southcentral (3 trials) 186.1 134 193.0 164 207.9 183
Southeastern (7 trials) 211.7 124 216.0 154 217.9 184
SW / West Central (12 trials) 183.4 139 189.5 169 202.6 194
SW / West Central (2 trials) 197.7 134 211.2 165 216.7 196
Southeastern (7 trials) 199.2 158 208.2 188 210.3 218
Southcentral (1 trial) 176.5 150 178.9 180 180.0 210

From these yield results, trends and patterns are observed:

  • Farmers can do a quick overall economic comparison of change in yield as it pertains to change in nitrogen application
  • All sites have been statistically evaluated with standard data evaluation tools for data significance
  • In corn on soybean sites with increased rate N was not economically viable in two out of the five regions (northeast + southeast)
  • In corn on soybean sites with increased rate N could be economically viable in two of the five regions (southwestern / west central + south central)
  • At all sites, yield loses were measured on the lower N rate verses farmer N rate.



Nitrogen Applied Rate

2018 Average Yield Results (bu./acre) by Precipitation


  Lower Rate N


Farmer Rate N


Increased Rate N


Precip. Averages (Apr-Jun inches) Climatic Averages

(Apr-Jun inches)



7.00 – 14.99 inches (15 trials) 196.0 201.2 208.0 9.67 9.52 +0.15
15.00 – 22.00 inches (15 trials) 195.1 200.7 214.7 18.71 11.30 +7.41
16.00 – 19.99 inches (4 trials) 191.6 201.4 200.2 17.58 11.15 +6.43
20.00 – 22.00 inches (6 trials) 200.0 208.8 214.4 21.00 11.98 +9.02

From these yield responses, trends and patterns are observed:NOTE: Trials were sorted evenly and separated into precipitation categories above. Yield averages were calculated by averaging trials in precipitation categories and sorted by previous crop.

  • Corn on soybean trials showcased the highest response to the increasing nitrogen rate above the farmer nitrogen rate, especially with the increased rainfall.
  • This data would indicate that nitrogen management decisions are very important based on increased precipitation rates during April – June timeframe. 


Looking Ahead

Over the next few months, AFREC will be working to further analyze 2018 on-farm trial data and release additional insights.

For the 2019 season, 29 trials were established.  In early 2020, data from those will be available. This analysis will evaluate interactions of treatments with three to four variables. The 2019 trials included these factors:

  • Nitrogen rate response
  • Sulfur rate response
  • Potassium rate response
  • High yield management practices

“Collecting good quality data will help whether from private or public research will help farmers to make their operations more efficient and profitable while keeping an eye on soil and water quality concerns.” adds Wiebers.

At AFREC, we agree. Our goal is to enhance soil fertility insights, and we will continue to fund research to provide that opportunity.

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