Getting plants to do your tillage

Nick Stokman and Ian McDonald have more than 80 years of combined experience in farming, research and extension. Yet they’re relative newcomers to the practice of bio-strip tilling, a means of replacing tillage implements with plants.

McDonald, a crop innovation specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs, learned of bio-strip tilling from southern Ontario farmers Lawrence Hogan and Steve Howard.

It’s a complex regimen requiring constant adjustments and monitoring.

“It’s an ongoing system and you have to be flexible and ready to react to what the spring looks like relative to the amount of cover crop growth and weather conditions,” McDonald said. “You talk to these guys – like Nick, Lawrence and Steve – and they’re excited about this.”

Stokman, who farms near Strathroy in southwestern Ontario, started bio-strip tilling in 2020 after decades as a no-tiller. He had also experimented with vertical and strip till.

Then he heard about Hogan and Howard, along with research by Laura Van Eerd and Josh Nasielski from the University of Guelph, and decided to learn more.

Bio-strip till systems revolve around two cover crop recipes seeded into a field as bands of “wheel rows versus corn rows.”

The wheel row recipe has overwintering species that offer living roots and nutrients for both the soil biome and the new corn crop.

The cover crop in the corn row will terminate with winter frost, and the remaining above-ground residue can be pushed away where the corn seed will be planted in spring.

A row-cleaning implement with two sets of planter row cleaners per corn row is pulled through the field prior to planting, resulting in a seed bed that’s been “tilled” by plants.

Living plants in the wheel row define where implements will travel so the area where corn is planted sees almost no traffic. The living plants also offer better weight-carrying capacity than tilled ground and reduce the potential for soil compaction.

The cover crops are terminated with herbicide before or after corn planting, depending on the year and level of growth.

“No-till wheat into soybean stubble works perfectly and no-till beans into corn stubble works really well,” said Stokman, who supervised the Strathmere Lodge Research Farm in Strathroy for 31 years.

“But that no-till corn into wheat stubble or a fairly heavy cover crop can be a little iffy. I’ve tried different things to get a little black dirt in the springtime so it warms up quicker and doesn’t take as long to dry out.”

Impediments

Bio-strip tilling is not a simple process, but Stokman and McDonald say the biggest challenge is mindset, especially getting past the previous status quo of aggressive tillage.

Defining soil health, or even measuring it, is another difficult concept. After 30 years in no-till, Stokman thought he had healthy soils, but learned they weren’t as good as he thought courtesy of the Yield Enhancement Network project in wheat.

“The first year of bio-strip tilling [2020], I had tillage radish and I like what it did, but I was concerned about the effect on the mycorrhizal fungi,” said Stokman.

“But I talked to Laura Van Eerd and she said there’s enough other material with my oats in the wheel track and that it shouldn’t be a concern. The big leaves tend to shade out some of the weeds and it really breaks down nicely over the winter.”

For his third year with the practice in 2022, he planted a modified cover crop recipe, seeding forage peas (one part), Austrian winter peas (half part), fababeans (one and a half parts) and sunflowers (half part). This year, he dropped the Austrian winter peas, moving them to the wheel track and replacing them with tillage radish in the corn row.

Row cleaner expense

McDonald said growers need only replace their tillage implements with a row cleaner. A good tractor, sprayer, planter and combine make up the list of equipment most growers have already.

“So much of this is about residue management and so many people believe that can only be done with tillage implements,” said McDonald. “What I’m trying to say is that residue management is a system of combine set-up and technology—about managing cover crops and about the planter.”

Row cleaners can be built for roughly $2,500 per unit, depending on the availability of parts. For his own unit, Stokman found a row cultivator, used brackets from some Yetter row cleaners and retooled some spider wheels he purchased at auction.

McDonald notes a grower from east-central Ontario paid $15,000 for a six-row unit earlier this year.

Still, champions of the practice say the savings in time and fuel are undeniable, and those who’ve adopted the system stand by it.

“The responses I’m hearing back from those others are all positive,” McDonald said. “Their yields are as good or better than their conventional-till neighbours, their time is less, their costs are less and their time factor in terms of planting and harvest are no different than anyone else.

“It’s just that they’re not spending time plowing and money tilling and maintaining tillage implements and additional tractors.”