Increasing Single-Pass Corn Stover Yield by Combine Header Modifications

Abstract

HighlightsRotary knives were added to an ear-snapper header to increase corn stover yield in a single-pass biomass system.Stover yield increased with the number of knives but at the expense of combine productivity and fuel consumption.Bale moisture was often greater than would be considered appropriate for good aerobic conservation.Abstract.Modifications were made to a conventional ear-snapper corn header to increase corn stover yield when a single-pass round baling system was integrated with a combine harvester. To collect more leaves and top portions of stalks, knives oriented parallel to the deck plates were added to shear crop material above the ear-snapper rolls. Stover yield was primarily altered by the number of knives on the header; and to a lesser extent by the fore-and-aft position of the knives and the header height. The number of knives on a 12-row header was varied from two to six in increments of two. Stover yield increased linearly with the number of knives, and dry basis stover yield ranged from 1.1 Mg ha-1 (no knives) to 3.6 Mg ha-1 (six knives) over the five years of data collected (2012 to 2016). Combine productivity decreased linearly and specific fuel consumption increased linearly with greater stover yield. Combine productivity declined by as much as 50% when six knives were used. Dry basis bale density decreased linearly with the number of knives because the dense cobs became a smaller fraction of the total bale mass. In three of the five years, bale moisture increased linearly with the number of knives; in those three years, bale moisture was typically greater than 30% (wet basis). Adding knives to the header increased single-pass stover yield but at considerable cost to combine harvester productivity, and aerobic bale conservation would be challenged by high bale moisture. Keywords: Baling, Combine, Corn, Density, Moisture, Productivity, Stover, Yield.

Intake of corn stover botanical parts by growing and finishing beef steers

“…SPB were produced by researchers from the University of Wisconsin-Madison Biological Systems Engineering Department using harvest methods as described in Keene et al (2013) . The combine harvester was equipped with a 12-row ear-snapper header equipped with knives on six rows that increased the inclusion of the upper portion of the stalk ( Walters et al, 2020 ). CST bales and SPB were stored on a concrete floor inside a pole barn.…”

Techno‐economic assessment of single‐stream feedstock logistics supply chain for corn stover and grain

“…The BCH maintains the advantages of co‐harvest, storage, and transport of the grain and stover while producing a whole‐plant feedstock with a larger fraction of intact grain than with the SPFH 10 . However, the harvest rate is significantly limited by the combine's capacity to thresh grain at high stover capture rates 5 …”

“…The operating ground speed for both single‐pass MES harvesting systems was taken from Walters et al 5 . (Table 4).…”

“…The MES header is an ear-snapper header where rotary cutoff knives have been added above the snapping rolls to increase the amount of stover collected. 5,10,12 The MES header preferentially collects the upper portion of the plant, which is less recalcitrant to pretreatment and bioconversion. Alternatively, the whole plant header cuts the plant completely from the root system at the designated cutting height.…”

“…In split‐stream systems, the grain and stover are separated by the harvester, transported, and stored separately. These include single‐pass bulk and single‐pass bale formats, outlined in Walters et al 5 . and Shinners et al ., 6 respectively.…”