Terry Smith says the main difference between the “good, deep topsoil fields in Iowa” and those in the area where he farms near Walcott in Greene County, Ark., comes down to one thing: organic matter.

That high organic matter translates into increased water infiltration, said Smith, who farms with his son, Clay, at S & S Farms. Both gave presentations at the Arkansas Soil and Water Education Conference at Arkansas State University.

“We’ve been up there, and one of the things you notice is their ditches at the end of the field aren’t washed out and gullied like ours are,” he said. “That’s because the water goes into the soil rather than running off the fields like many of the Mid-South soils do.”

The Smiths began looking at cover crops after watching a rainfall simulator demonstration by Keith Scoggins, district conservationist with the USDA Natural Resources Conservation Service in Cross County, four years ago.

The demonstration compared the water infiltration rates for two different soils on the Smith Farm after a 1-inch rain event.

“We took two slabs of dirt — one from what we call a sorrier soil with a cover on it and some of our best dirt that didn’t have a cover,” he said. “The water falling on our best dirt just ran off while the water on the other slab infiltrated into the soil.

“Then we discovered through Dr. Green’s plots and through larger field trials on our farm how these benefits showed up.” (Dr. Steve Green is an agronomist with Arkansas State University.)

The father and son started with a small acreage of cover crops. In 2019, they expanded to 1,200 acres of cover crops and, last fall, they planted 1,700 acres of cover crops for termination this year.

They’ve also begun using soil moisture sensors and are planting different species of cover crops for their corn and soybean fields. “This year, as Adam Eades alluded to, we’re also trying cover crops for a furrow-irrigated rice demonstration on our farm.”