A U.S. propane industry group is touting the concept of injecting steam into soil to kill weed seeds, but other research shows difficulties in heating soil to a high enough temperature to kill weed seeds with a mobile implement.

Two application methods highlight efficacy rates and cost differences
Science Brief: Combining harvest weed seed control with early-maturing crops may limit wild oat populations
The Seed Terminator, an attachment that destroys weed seeds on their way out of the combine, is being put to work on a farm north of Saskatoon