Dave Stark has a passion for agricultural science, especially the science of crop residue.

“Leaving crop residue definitely adds value,” he says. 

Stark, the president of agriculture at Holganix based in Aston, Pa., is a Ph.D. molecular biologist and biochemist. He works to help farmers better understand the composition of crop residue, including the different types of residue and the ways they can impact a no-till operation.

Residue minimizes erosion, preserves moisture and provides nutrients for subsequent crops. Properly utilizing crop residue is important right now because of the high cost of inputs, Stark says.

“For about every 40 bushels of corn you produce, you produce about a ton of residue,” he says. “For a 200 bushel-an-acre crop, you’ve got 5 tons of residue per acre. Each ton has a lot of nitrogen (N), phosphorous (P), potassium (K) and sulfur. This has value, especially with fertilizer prices the way they’ve been. We want to make sure we get those nutrients back into the ground.”

Microbial Products

The crucial thing for no-tillers to focus on when looking at how to ensure decomposition of crop residue is microbial activity, Stark says.

“Nothing else breaks down the residue and releases nutrients,” he says. “The more we damage the residue, the more entry points for the microbes, and the more soil contact we have.”