On crops such as lentils, canola and wheat, Ruwoldt sees as much as a 100 to 300 per cent increase in production on crops where there has been no vehicle or machinery traffic, compared to areas of the field where there has been one or more passes with equipment.
wheel marks where a heavy infestation of wild oats grew. In another example, he showed a photo of a conventionally farmed neighbour’s field — same soil type — where after a heavy rain, water had ponded to form a shallow lake. On his adjoining field, where he practised CTF there was no standing water. He hasn’t seen standing water on his land for 25 years.
Ruwoldt believes even light compaction affects water infiltration into the soil, and after repeated trips over a field, an impermeable layer of soil can form a few inches below the soil surface. This can cause crop roots to “hockey stick” as they reach that layer, and be unable to reach nutrients farther down.
HOW TO SET UP TRAMLINES
It does take an adjustment of management and thinking to gear all field operations to travel only on permanent tramlines. Ruwoldt based his CTF system on tramlines on 10-foot wheel centres, spaced 30 feet apart. The width of all field equipment is in 30-foot increments. For example, he seeds his 7,000 acres with a 30-foot-wide drill, travelling an average of 10 m. p. h.
Ruwoldt emphasized that CTF is part of a farming system. He practises zero-till farming, and also pays particular attention to managing and protecting crop residue. Again, as part of the system, he uses wide-row spacing on all crops — 15 inches for cereals and 30 inches for canola and dry field beans. While he uses GPS guidance systems for field operations, he has upgraded to RTK (real time kinematics), which provides one-inch accuracy. This is an important tool for inter-row cropping. He is careful to leave all of last year’s stubble standing and seeds the new crop between the stubble rows.
Ruwoldt has dramatic photos of large, robust root systems of lentils grown on the inter-row cropping system, compared to smaller plants from conventional farming, and of five-foot canola plants with a four-foot-long tap root “the size of a carrot” compared to a two-foot-tall canola plant with a shallow root mass. The wider spacing and good soil structure allow roots to grow large and deep, he says.
Research at Agriculture and Agri-Food Canada’s centre in Swift Current, Sask., has also shown a 12 per cent yield advantage from inter-row cropping, along with other benefits such as improved weed suppression, fewer root diseases, improved crop emergence, improved seeding depth accuracy, and more even crop maturity.
As Larocque is preparing for his first CTF season in 2010, he’s using Concord air drill cart also has to be narrowed by about four inches on each side. The field sprayer and combine were factory built with wheels on 10-foot centres.
a model similar to Ruwoldt’s. He’ll base the tramline on machinery wheel traffic with 10-foot spacing, and the width of all field equipment on 30-foot increments.
He plans to modify (reduce) the wheel spacing on his Steiger tractor by eight inches on each side of the axles to bring it down to 10-foot centres. The wheel width on his He will also reduce the width of his air drill tool bar from 40 to 30 feet. Fortunately it was built with five-foot-wide sections, so he can remove the last wing on each side. The combine is already equipped with a 30-foot centre-mounted header, and the field sprayer has a 90-foot boom, which is another multiple of 30 feet.
While he will keep the 12-inch row spacing on the air drill, he does plan to go to a narrower opener to reduce soil disturbance and moisture loss, and have a narrower seed band for inter-row cropping.
The drill is currently equipped with four-inch low-draft Gen openers, which allows him 60 to 70 per cent accuracy for inter-row cropping even with standard GPS. He plans to convert the drill to narrower 1.5-to two-inch-wide Dutch openers.
“I have no doubt this system will work in Western Canada, but it may not be for everyone,” says Larocque. “I don’t think we realize as farmers how much we are giving up to soil compaction. Restricting field traffic to just the tramlines is the beginning, but one other operation we have to pay particular attention to is residue management. Because we are using the same tramlines each year, we have to make sure crop residue is distributed evenly.”
Lee Hart is a field editor for Grainews in Calgary, Contact him at 403-592-1964 or by email at [email protected]