• Plant Health

Be Confident In Soil Sampling Results

Man standing in a field holding a soil sampler probe.

Establishing an effective fertility program is not a simple task nor a small investment. Whether you soil sample in spring or fall, you need to be able to trust the results so you can make confident fertilizer decisions, but accurate results only come from samples that are properly and consistently taken.

Take accurate soil samples

At SureTech® Laboratories, we always say quality starts in the field. A testing lab can have the best processes in place and the most advanced quality control but if there are inconsistencies in the way samples are taken, inconsistent results will occur.
To ensure accuracy, soil samples need to:

  • Be taken at the same time of the year.
  • Be taken at the right depth of 6 to 8 inches consistently.
  • Contain an adequate number of soil cores to accurately represent the area.
  • Use the most appropriate sampling method depending on a farmer’s strategy. Most farmers use a grid sampling method, where samples are taken every two and a half acres. This helps indicate soil variability in a field and is necessary if you’re going to do a variable-rate fertilizer application. 

Making fertility decisions based on poor soil samples can lead to lost dollars from overapplication of fertilizer. You could also underapply, resulting in limited yields, lost revenue or both. 

The consequences of not soil sampling

Soil testing typically accounts for a small percentage of your total cost per acre when you consider seed, fertilizer and crop protection products. A typical soil test costs about $7 per sample, representing a two and a half acre grid. Yet some of the most critical decisions you make during the season are based on that information. If you’re not soil sampling and you’re applying fertilizer, you’re operating blind.

New soil testing method available to further advance lab quality

A few years ago, at SureTech, we switched our pH testing procedure from a water-based method to a salt method. This new way of testing helps minimize any seasonal or weather-related effects on pH. Previously, if there was dry weather, a pH test could reflect an artificially lower pH level due to the high salt content in the soil. If there were wet conditions, pH levels might be artificially higher because some of the salt had leached out. Using a salt pH testing method provides more consistent, less seasonally affected pH numbers. 
We’re working with the WinField United Innovation Center on several trials to determine what the most advantageous testing options are for farmers. The more data on each acre we can provide, the better the decisions farmers will be equipped to make about optimizing their fertilizer dollars. Talk with your local trusted advisor about the right soil testing process for your fields.
All photos are either the property of WinField United or used with permission.
This article was originally published in March 2020 and was updated in April 2021.

© 2021 WinField United. Important: Before use always read and follow label instructions. Crop performance is dependent on several factors many of which are beyond the control of WinField United, including without limitation, soil type, pest pressures, agronomic practices and weather conditions. Growers are encouraged to consider data from multiple locations, over multiple years and to be mindful of how such agronomic conditions could impact results. SureTech® and WinField® are trademarks of WinField United.