“Often row crops that we grow just suffer too much growth and yield depression when they are seeded in zero-till conditions.”
– JOHN HEARD
It’s hard to beat warm, black soil for spring seeding. But under the zero-tillage doctrine, which places great importance on the moisture retention and soil preservation advantages of retained trash cover, heat-loving crops such as corn, sunflowers, dry beans and sugar beets may end up getting off to a slow start in cool, wet soil.
Fall strip tillage can be used to part the surface stubble and open up narrow rows of bare soil to the warming rays of the sun. Then, with a high-precision RTK guidance system, seed can be put down right in the middle of the strips.
The practice, common south of the 49th parallel and catching on in Ontario, may offer the best of both worlds, according to MAFRI soil fertility specialist John Heard, who gave an overview of research results on the possibilities of using the system at the Manitoba Zero-Tillage Research Association annual general meeting at CMCDC Carberry last week.
“Often row crops that we grow just suffer too much growth and yield depression when they are seeded in zero-till conditions,” said Heard.
New concepts in farming have come and gone over the years, added Heard, who recalled from his student days 25 years ago at Purdue University how he was convinced that fall ridge till for row crops was the way to go for reducing the yield gap between no till and conventional tillage.
But the last he heard, only about six farmers are still using ridge till, even in the practice’s former heartland, southern Minnesota.
“In 25 years, it has gone from hero to zero,” he said, adding that although yield advantages for some crops were “spectacular” compared to chisel plow systems, it didn’t work well with narrow row crops such as wheat, which tended to drown out in the dips, and thrive on the ridges.
No-till soybeans are easy, just like peas. But the big challenges are for corn-into-corn stubble, and corn following wheat.
Strip tillage, which opens up a band six to 12 inches wide, will be tested at the annual crop diagnostic school in Carman, CMCDC Carberry and the WADO research farm in Melita this summer, offers advantages in the form of less field work and erosion risk, and the layer of trash residue conserves moisture between the rows.
The strip tillage unit to be tested is made by Elmer’s Welding in Altona. It features a series of tillage tools that operate in sequence as it is drawn over the field. First is a round coulter, followed by a set of row cleaners to separate residue in the row, then a tillage shank that can be used to band fertilizer. After that comes a pair of berm-building discs, and a conditioning basket to break up clods.
Heard said that research from southern Minnesota showed that zero tillage leaves the soil cooler in the spring than chisel plowing, and fall strip till offered the highest soil temperature of all.
As a soil fertility specialist, Heard believes that the most compelling reason to strip till might be more efficient fertilizer use if phosphorus and potash can be placed precisely within the rows and allowed to “mellow” over the winter, rather than the typical practice of surface broadcasting.
Ontario farmers have found that strip till has found its niche, even if it is used with one crop in a rotation.
“Zero-till soybeans into corn is a cinch, winter wheat into soybean stubble is a cinch. You can kind of zero-till corn into soybeans, but zero till corn into wheat or corn stubble is a loser,” said Heard.
“It’s that one crop in a rotation that they need strip for; they’re not doing it for all crops.” [email protected]