In a recent article on reducing the number of Palmer pigweed seed carried over into the next season, we reported on the concept of narrow windrow burning, a system initially developed in Australia.
The windrows are formed as chaff or residue exits the combine. Essentially, a set of steel plates mounted on the rear of the combine funnel the residue – including weed seed – into a 30-inch-wide windrow.
From there, it’s simply a matter of burning the windrows.
In a paper published in the scientific journal Weed Science, a team of U.S. and Australian researchers conducted multi-year comparisons of several approaches to reducing the number of Palmer pigweed seed that would end up in the soil’s seed bank. The study looked at a range of common and non-so-common approaches.
Narrow windrow burning scored among the top 3 methods.
As researchers found, narrow windrow burning destroyed 100% of the weed seed within the burned windrow, says Jason Norsworthy, a University of Arkansas weed scientist and one of the study’s authors.
That’s not to say some seed weren’t scattered between the windrows, but a significant portion of Palmer seed made it into the fire.
When the windrow is not burned – which might be the case under certain environmental conditions – more weed seed survived, “but you get a good bit of decay during the winter months, and we still saw a positive benefit,” Norsworthy says.
Adding the chute to a combine could cost around $200, according to Norsworthy, who already has received 40 to 50 requests on how build one.