AS FARMERS adopt more conservation tillage and no-till practices, residue management plays an increasingly important role as a nutrient-release mechanism for subsequent crop rotations.

Nutrient release from residue is important for subsequent crops, and research shows that the proper mechanical sizing of residue, combined with fall application of biocatalysts, enables increased residue degradation thus resulting in higher yields for both corn and soybeans, says Alison Vogel.

The research assistant at the University of Illinois estimates 40-60 pounds of stover, or above-ground biomass, is generated per bushel of corn. The approximate values of key nutrients in corn residue includes nitrogen (N) at 20 pounds per ton, phosphorus (P) at 4 pounds per ton and potassium at 23 pounds per ton. Assuming a 300-bushel yield per acre, 10 tons of corn residue would result in 200 pounds of N, 40 pounds of P and 230 pounds of K per acre.

“So all of these nutrients are in the residue at harvest, and we want to utilize that for next year’s crop,” Vogel explains. “We’ve been investigating residue degradation and getting the nutrient release to line up with crop demand, using both mechanical and chemical applications of residue management. Whether this is for subsequent corn or soybean crops.”

Two Approaches 

Vogel’s study involved comparing residue degradation rates and crop yields using both mechanical and chemical treatments. 

When it came to post-harvest residue management treatment options, the two mechanical treatments compared included standard corn-stalk rollers and Calmer’s BT Chopper stalk rolls. While some standard…