Single-Pass, Single-Stream Harvest of Corn Grain and Stover: a Comparison of Two Harvest Methods

The single-pass, split-stream harvest of corn grain and stover has been extensively studied. Challenges for these systems include the logistics and economics of handling separate grain and stover streams. Single-pass, single-stream processes have been explored using a self-propelled forage harvester to collect whole-plant corn as a biomass feedstock. However, due to the processing done by the self-propelled forage harvester, a significant portion of the grain fraction is damaged during harvest limiting its marketability. To evaluate an alternative system, a combine harvester was modified with a rear blower to collect corn stover, facilitating the collection of the grain and stover fractions into the same wagon, creating an aggregate, whole-plant corn material. Utilizing this system, a plot study was conducted to compare it to a self-propelled forage harvester. Parameters studied for system performance were yield, grain damage, and geometric mean particle size. While the combine system reduced grain damage (p < 0.001) by 18 percentage points compared to the self-propelled forage harvester and had a similar whole plant particle size (p = 0.11), it collected 1.86 Mg DM ha⁻¹ less biomass (p < 0.001). The combine harvester with a stover collection system provides a method to collect whole-plant corn as a biomass feedstock that maintains a large portion of the grain integrity but decreases dry matter yield.