Precision soil testing helps farmers manage fields better

By Scout Nelson

John Brecker, a soil scientist at Agvise Laboratories in North Dakota, has observed soil testing trends across North Dakota and Manitoba. He notes that about 50% of soil samples in these areas feed into precision systems, while other regions like South Dakota and Minnesota show up to 80% of samples using precision techniques.

Brecker explained that only 20% of the fields serviced use precision sampling, and there are regional differences within Manitoba. In some eastern areas, precision sampling is minimal, while areas like Roblin see rates as high as 86%.

The reason for these regional variations is largely due to topography. Western regions with varied landscapes, such as eroded hilltops and low-lying depressions, make a strong case for precision soil sampling.

Conversely, the Red River Valley is often perceived as flat, though Brecker stresses that yield monitor data shows significant variability in yields, which supports zone sampling.

Weather conditions also play a major role in soil nutrient levels. Brecker referenced the severe drought of 2021, which left unusually high residual nitrogen levels across the Great Plains. Following canola and wheat crops, residual nitrogen reached an average of 65-66 pounds, far exceeding the normal 25-35 pounds. By 2022, much of that nitrogen had moved deeper into the soil due to wet conditions.

In 2023, despite dry weather, residual nitrogen levels varied between wheat and canola fields due to temperature fluctuations. Wheat showed 51 pounds of residual nitrogen, while canola had closer to average levels at 36 pounds.

Brecker emphasized the importance of annual soil testing, saying, “That’s why we soil test every fall, to really try to point out how these environmental factors that we can’t really predict are going to show up.”

Testing, particularly in a zone system, allows farmers to make informed decisions about field management, ensuring better outcomes in unpredictable conditions.

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