Farming for Sustainability: Understanding Tillage

Have you ever seen a vintage photo or illustration of a farmer laboring in the field with an ox-drawn plow? It would take a farmer with one ox about one day to plow a single acre!

Fortunately, farm equipment has progressed—as have farming practices. Today’s farmers use a variety of tillage implements and strategies, depending on their specific situation.

Brad Ruden, agronomy tech services manager at Agtegra Cooperative says, “Growers are trying to get the most productivity they can out of their soils. It may mean no-till in some areas. It may mean focused tillage or full tillage in others.”

Today, farmers most often use implements such as field cultivators, discs or vertical tillage implements. This type of equipment shifts the top layers of the soil but doesn’t disturb the soil structure below.

Why till?

In the past, tillage was used to bury weeds and create a smooth, black seedbed in preparation for planting. “With our current technologies we can easily plant in a no-till situation,” Ruden says.

Tillage plays a significant role in certain areas of the state. While South Dakota farmers have traditionally focused on keeping moisture in the soil, those in the southeastern part of the state can be challenged with too much moisture—especially in years like this one.

“Farmers today use tillage to break down the crop residue that’s left in the field from the previous season, and cycle it back into the soil,” Ruden says. “Sometimes residue can be negative because it can keep soils very, very cold in the spring.”

Ruden explains that tillage does help dry out the soil, but not without risk. “Tillage would be desirable to help these soils to warm up. But it’s easy to compact soils with heavy equipment, and that’s more likely to happen when soils are wet.”

Why no-till?

According to Ruden, the most common tillage production practice in South Dakota is no-till.

After harvest, farmers simply leave the cornstalks or soybean plants in the field to decompose. This builds the soil’s organic matter and nutrients.

No-till also maximizes the soil’s ability to absorb water.

“In much of our state, water management really is the critical limiting factor in crop production,” says Ruden. “It’s the fact that we just simply can't get enough moisture to these plants, regardless of anything else we do, to be able to maximize our yield potential.”

Some of the tillage practices of the past actually harmed the soil. “We never really understood soil structure well enough to know what all those aggressive tillage methods like plowing did to our soil structure,” Ruden says.

“More recently, we’ve realized that we were creating what we would call a tillage layer in that field, where we were compacting a layer of soil at the bottom of that plow level. So then we would create a very, very dense layer of soil in there. Our crops’ roots simply couldn't penetrate through that.”

Farmers don’t want to restrict root growth. “That's where the no tillage situation came in. But then we have to manage the things we're creating as well, like residue,” says Ruden.

Why strip-till?

Fortunately, tillage isn’t an all-or-nothing farming practice. There’s an entire spectrum of options, including minimum or conservation tillage and focused tillage.

“We also do strip-tillage in some areas,” Ruden says. “We apply fertilizer in a very narrow band. And then we’re tilling that band of soil in the fall of the year to allow that particular soil to be able to warm up in the spring and provide us a nice planting bed.”

With strip-till, farmers still realize many of the benefits of no-till. The rest of the field cycles residue and absorbs moisture.

Focused tillage is another option. According to Ruden, farmers will till specific areas for weed control when other weed management strategies aren’t working.

Striking a balance

Tillage works hand-in-hand with other farming practices, such as crop rotation, cover crops and focusing on soil health.

Many farmers adjust these practices from one year to another to maximize sustainability and productivity.

“Finding the right balance is part of the art of agriculture,” says Ruden. “And that's why having that partnership between a grower and an agronomist and finding the right balance of things to do on that farm is so important.”

“But I think our growers do it better than anybody in the world,” he adds. “That’s what we’re all about.”

If you have questions about farming practices, please contact South Dakota Corn at 605-334-0100.

Tillage video footage provided by Great Plains Manufacturing.

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