Strip-Till Merges Benefits of Tillage and No-Till
If you’re looking to merge the conservation and soil health aspects of no-till while preserving the soil warm-up perks of conventional tillage, strip-till may be for you.
Under strip-till, farmers till narrow 6- to 12-inch-wide strips between rows. Fertilizer is often injected into the strip during strip-tilling. Tilled strips correspond to planter row widths of the next crop. Next spring, seed is planted into the tilled strips. Farmers normally strip-till in fall after harvest, but it can be done in the spring before planting.
Last month, the University of Minnesota (U of M) and North Dakota State University (NDSU) hosted a Strip-Till Expo at their research sites near Fergus Falls, Minnesota. They noted that strip-till:
- Conserves energy and fuel because only partial tillage occurs.
- Reduces soil erosion. That’s because crop residue covers most of the soil throughout the year. The residue blanket also conserves soil moisture.
- Releases less carbon into the atmosphere and maintains higher levels of soil organic matter.
- Warms the tilled strips sooner in the spring to promote seed germination and plant emergence.
- Reduces expenses by eliminating some primary and secondary tillage.
What’s the Yield Impact?
If you’re looking at the monetary impact of strip-till, look at return on investment via reduced fuel and machinery costs rather than a yield spike.
Soybean yields in a corn-soybean rotation have been similar between the following systems over 13 years of U of M trials:
- Vertical till (2 passes)
- Field cultivation (1 pass in the spring)
- Chisel plow with a field cultivation
Mixed findings have occurred with corn. Overall, corn yields have been similar regardless of what tillage system was used, says Jodi DeJong-Hughes, U of M Extension crops educator. On corn-on-corn, though, differences emerged later between less- and more-intensive forms of tillage.
“In the third year of the corn, when residue builds up on the soil surface, is when we started seeing yield differences,” says DeJong-Hughes. It’s then when some form of tillage – such as strip-till and chisel plowing – cleared the residue that was dragging down yields.
Strip-till corn has yielded both above and below yields of soil that’s been chisel plowed or vertically tilled in NDSU trials. However, extenuating circumstances are often involved when lower yields have occurred.
In a 2015 NDSU trial, 200-bushel corn yields in a corn-soybean rotation occurred across multiple tillage systems, says Aaron Daigh, a NDSU soil scientist.
“There were no yield differences between any tillage options, except for one set of strip-till plot that yielded 7 bushels less than the rest,” he says.
In this case, all other tillage systems were planted during good weather. However, rain delayed planting the strip-till plot set. “When we finally got in, it was wetter than what we wanted, so we got some smearing in it when we did the tillage,” says Haigh. “The yields were hurt from tilling while the soil was too wet.”