Good News for Biomass in the Field
We’ve heard both sides of the crop residue harvesting argument time and time again, but new data—data gathered from people actually on the ground for a real, ongoing advanced biofuel project—says that crop residue can be a responsible part of good farming management.
POET-DSM Advanced Biofuels Joint Venture released the research earlier this week, which was performed by scientists from Iowa State University and the USDA. In a nut shell, they studied six different harvest methods in an effort to provide area farmers with data to help them make decisions about biomass harvesting. So far, the verdict is that as long as they following recommended removal rates—rates that Poet-DSM stands by—there are no reductions in yields.
Poet-DSM contracts for about 1 ton of biomass—in this particular project its corn waste such as stalks, cobs, etc.—per acre with participating farmers, which is apparently less than 25 percent of the available above-ground biomass. They are contracting for 85,000 tons this year, and once operational, Project LIBERTY will require about 285,000 tons per year.
Larry Ward, senior vice president of project development at Poet, pointed out that the project isn’t boarding on the line of being unsustainable (harvesting JUST enough to whereas there won’t be any damage) but rather, they are well within responsible harvesting limits.
Nutrient replacement post-harvest is minimal, one of the lead researchers said, and there’s no evidence that nitrogen needs to be replaced, though Poet-DSM recommends the addition of 10-15 pounds of potash when soil tests indicate it is needed.
Additionally, the effects of biomass harvesting on soil carbon have also proven to be minimal according to the report’s measurements of soil organic carbon, and more an effect of yield and tillage intensity than biomass removal.
Farmers’ worries about harming their soil are certainly warranted, but hopefully this and future research will help assure them that as long as it’s done carefully and properly, it can be a profitable—and rewarding—endeavor.
Here is a link to the full, detailed report.