Controlled traffic farming barely rates a blip on the radar of farming practices across the U.S. today. But that could change as farmers become more aware of the yield-boosting potential of using real time kinematic (RTK) navigation systems to guide implements over the same tracks year after year.
At least that’s the hope of promoters of controlled traffic farming, which they say not only increases yields, but also cuts fuel costs, reduces machinery wear and tear and curtails erosion.
“I absolutely see it growing,” says Trevor Mecham, Advanced Farming Systems (AFS) marketing manager for Case IH. “The RTK infrastructure is in place across the U.S. to make it possible to drive on the same spot every year. Science shows this will improve yields, reduce production costs and enhance our soils.”
“It is foolish not to consider controlled traffic farming when you have RTK,” says Randall Reeder, a longtime agricultural engineer at Ohio State University who worked with farmers on reducing its impact of soil compaction on crop yields. His advice: “Don’t reject controlled traffic because you can’t get everything lined up perfectly.” You’re still likely to see productivity improvements even if your system is less than perfect, he says.
Yield gains: 5 to 8%
Reeder’s research on soil compaction highlights potential yield gains from controlled traffic systems, which are designed to concentrate compaction in traffic lanes and avoid compaction across the rest of the field.
“Our research, which is comparable to research around the world, shows that we are losing 10% of yield because of compaction,” Reeder says. His research mimicked random traffic patterns typical on many farms, which can result in traffic covering 80 to 90% of a field over a two-year period.
Reeder pegs net yield gains from a rigorous controlled traffic system at 5 to 8%, since yield will still be suppressed in rows adjacent to controlled-traffic lanes.
Lower fuel, repair bills
Farmers using controlled traffic systems typically spend less money on diesel fuel, because driving on a compacted track is more efficient than driving on tilled soil, Reeder says. Repairs often are lower, too, because tractors and sprayers don’t work as hard as they cross the field.
“Tractive efficiency can double on firm soil compared to loose soil,” says Clay Mitchell, who uses a controlled traffic system on his east-central Iowa farm. He says his fuel cost savings for tractors and sprayers have been in the 40% range, but less for combines. Less wear and tear on drive trains has led to lower repair bills, Mitchell confirms. Running single tires instead of duals has cut his tire bill, too.
Reduced erosion is tied to improvements in soil structure that controlled traffic can bring. Less-compacted soils tend to be more permeable and thus able to absorb more rainfall before runoff begins.
A study on Mitchell’s farm conducted by an Iowa State University student showed that compaction in the track was similar to general compaction in traditionally farmed fields. Compaction fell off significantly away from traffic lanes.
“The difference is dramatic,” Reeder says. “We have measured high compaction in the track and good soil conditions away from the track.”