Changing tillage systems has increased the soil’s organic matter, which benefits the crops and keeps the soil from blowing away. I can see a difference in the fields we’ve been operating longer. My goal is to constantly grow organic matter, eliminate nutrient loss and improve water quality.

Kelly Nieuwenhuis

O’Brien County

Farming Operation

  • Third-generation corn and soybean farmer in northwest Iowa; farms with two brothers
  • 100% of their corn is used in ethanol production
  • 2021 vice president of the Iowa Corn Promotion Board
  • Member of the National Corn Growers Association’s Ethanol Action Team
  • Member of the U.S. Grains Council’s Ethanol Advisory Team
  • On the board of Iowa’s Renewable Fuels Infrastructure Program


4R Plus Practices Used

  • One-pass vertical tillage to work the ground 2 inches deep and leave 99% of residue on top
  • Installed grass waterways and filter strips
  • One-pass, low-volume urea application in the spring with nitrogen stabilizers and impregnated with pre-emerge herbicides; no use of anhydrous ammonia
  • Regularly testing tile lines to assess water quality
  • Flood-prone land enrolled in the Conservation Reserve Program
  • Soil testing every four years to determine nutrient needs

Results Seen

  • Vertical tillage has increased organic matter and has improved water holding, nutrient holding and carbon sequestering
  • Increased populations of earthworms, which are an integral part of the soil’s biology
  • Decreased the level of commercial nitrogen fertilizer applied
  • Waterways and filter strips catch nutrients and control erosion
  • Nitrate levels under 10 ppb (.01 ppm) in water from tile lines – the EPA nitrate standard for drinking water is 10 ppm



Plans for the Future

  • Continue to increase organic matter to improve soil for the next generation
  • Adopt improved technology – i.e., smart sensors that tell the temperature, moisture and organic matter in the seed furrow during planting; mapping to quickly find and fix problem spots in fields
  • Continue communicating with landlords on the advantages of conservation practices
  • Install waterways and filter strips on rented land where it will benefit the soil
  • Look for ways to produce more using fewer resources
  • Explore participating in the carbon credit market 

Click here to ask Kelly Nieuwenhuis a question about the farming operation.

Spring 2021: Multiple Advantages of Reduced Tillage

On the flat landscape in O’Brien County, Kelly Nieuwenhuis has been working to increase organic matter in the soil his entire farming career. After a long history in a full tillage program, he switched to one-pass vertical tillage in 2016 and has seen organic matter in the soil increase rapidly.

“We went to narrow, 20-inch rows in 2004, and in 2016, we switched to one-pass vertical tillage in the spring. Now we only work the ground 2-inches deep the day before we plant and leave 99% of residue on the top to protect the soil and absorb moisture,” he said. “Basically, we’re just airing out the soil and warming it up a little bit before planting.”

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