Trying to create more with less is what drove strip-tiller Zack Smith to experiment with the “weird stuff” on his farm in Lake Mills, Iowa. Some of those ideas include strip-till when it was a relatively new practice in the early 2010s, intercropping and what’s gained him attention most recently, an autonomous livestock barn that moves down the rows between strip-cropped corn.

Strip intercropping was Smith’s first experiment. In 2012, he planted alternating 30-foot strips of corn and soybeans to try to boost yield on the outside edges. The outside rows were planted at a population of 48,000, while the middles were lower.

“The ear weights were 370-380 bushels per acre on these outside rows,” Smith says. “The overall average that year was 250 bushels per acre in the strip intercropped rows, compared to 190 bushels for most of our corn that year from the drought.”

Smith and ag engineer Sheldon Stevermer tried variations on strip intercropping in the years that followed and got mixed results with their experiments. Eventually, they decided to focus on optimizing their strip-till setups — until the COVID-19 pandemic presented an opportunity to innovate in 2020.

“Locally, corn was $2.75 per bushel. Beans were $7.50 or $7.60 per bushel at that point,” Smith says. “It was tough. Even with all the efficiencies and advantages of strip-till, you’re not going to make money on $2.75 corn, so we started trying to brainstorm how to raise revenue without spending more money on the farm.”

That led Stevermer, Smith and Lance Peterson, a farmer from Rush City, Minn., back to the concept of strip intercropping. Peterson suggested putting livestock between the rows of corn instead of another crop. The idea then quickly evolved into the prototype of the Stock Cropper, a mobile grazing barn that guides a diversity of livestock between wide strips of corn.

The first iteration of the Stock Cropper launched June 14, 2020, with sheep and goats in the front of the barn, hogs behind it and two chicken tractors trailing it. The “four-ring animal circus” had an electric winch acting as an anchor, and Smith would move the contraption two or three times per day to keep the animals in fresh pasture.

“It’s the reintroduction of livestock and crops working together in a dynamic arrangement that can be rotated with the strips,” Smith says. “Next year, we’ll strip-till that, plant corn into those strips and have the benefit of this perfect closed-loop rotation where we go back and forth with animals feeding plants, plants feeding animals.”

In the first year, the animals grazed a six-way annual pasture mix that was mostly oats planted between rows of strip-tilled corn on corn. The oats proved to be too dominant in the mix, and Smith mowed them off and fed hay until the Stock Cropper had moved to a summer cover crop mix.

The first year taught Smith a lot about timing the Stock Cropper’s movement. In 2021, he created an expanded plot that had three Stock Cropper systems. One had four rows of corn separated by 10 feet of pasture with a 10-foot-wide barn traveling down the pasture rows. The same setup was replicated with 20 feet of pasture and a 20-foot-wide barn and 30 feet of pasture with a 30-foot barn. Smith also designed a “racetrack” pattern that allowed the barns to cover the same area twice in one growing season. By October, the animals are finished and ready for market.

To learn more about the Stock Cropper and the benefits it can bring, read Michaela Paukner’s article “Strip Cropping Corn with Livestock Pasture Raises Yields, Profits” featured in the Spring 2026 Issue of Strip-Till Farmer.