Trying to save money by not soil testing this fall may result in spending more on 2022 crop inputs.

“If there ever was a time in the last 30 years to soil test, this is it because the cost of fertility inputs are so high,” said Brad Brummond, North Dakota State University Extension agricultural agent for Walsh County.

By “shotgunning” the amount of fertilizer, either too much or too little typically is applied to fields, Brummond said.

Applying too little fertilizer can result in crops not reaching their full yield potential. Meanwhile, farmers who apply extra fertilizer to their fields risk not only wasting money if the amount is higher than it should be, but also causing environmental damage if it runs off fields into waterways, he said.

“Phosphorus loading is real,” Brummond said, noting that blue-green algae growth in nearby dam recreation areas and rivers is proof of that.

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It’s important to test soil every year because the amount of nutrients soils need varies depending on factors such as the crop that was grown on it and the amount of rain that fell during the growing season.

For example, this year, the amount of nitrogen in fields will likely be higher because the 2021 growing season was hot and dry, so plants didn’t utilize the nutrients as much as they typically do. Meanwhile, the fertilizer didn’t get the rain this spring that it need to “wash down” into the soil, Brummond said

“We’re going to have quite a little carryover fertilizer than we’re used to, simply because the plant didn’t burn through it.” he said. “There are nitrate levels over the top in forages. We’re going to see increased amounts of nitrogen.”

North of Walsh County, at the Langdon Research Extension Center in Cavalier County, North Dakota, soil tests conducted a year ago, in the fall of 2020 had a record amount of residual nitrogen, said Randy Mehlhoff, center director.

This spring, Mehlhoff applied one-fourth to one-half less nitrogen because the fall 2020 testing had shown the residual amount was high, he said.

Mehlhoff expects that the soil tests he recently completed and sent to the NDSU laboratory will also show that there will be residual nitrogen in fields this year.

“This year was a drought year, and yields were down, so I’m guessing the residual will be up,” he said.

If Mehlhoff’s prediction is correct, he will adjust the amount of nitrogen he applies to the research center’s test plots in the spring of 2022, accordingly, which will save him some money in input costs.

“I’m going to very much use that because the price of fertilizer is high,” Mehlhoff.