Stacking Up: Michigan Sugar Experiments With Field Cleaning & Stacking of Beets for Storage

Beet stacker at the Michigan Sugar piling station near Dover, Ont. Photo: Keith Kalso

The 2011 sugarbeet harvest marked the second year of an innovative — and successful — beet loading and storage project involving growers and staff of Michigan Sugar Company.  In this project, which has been conducted in the co-op’s Sandusky and Bay City, Mich., and Dover, Ont., districts, participating growers dump their harvested beets on field edges.  A Ropa ‘Maus’ machine cleans the beets before they are loaded into trucks and transported to the piling station.  There, a “stacker” conveyor places the already-cleaned beets into standard long-term storage piles.  The stacker is essentially a standard beet piler on which the grab-roll cleaning bed and dirt belt system have been bypassed or removed.

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Michigan Sugar’s goal for 2010 was to stack 50,000 tons of beets using this system.  By harvest’s end, more than 60,000 tons had been cleaned by Maus machines and stacked at the two sites.  In 2011, more than 135,000 tons were cleaned and stacked — nearly 72,000 at Dover and 43,000-plus at Sandusky.  An additional 20,000-plus tons were stacked at a third site west of Bay City.

    The cooperative initially considered — and still considers — this to be a research project.  “From a physiological standpoint, beet roots undergo a rest-storage phase once they are harvested,” points out Keith Kalso, agricultural manager for Michigan Sugar’s Croswell factory district.  “Removing roots from this phase usually ‘wakes them up,’ causing respiration, heat and then rotting.  The theory being tested has been to pile the crop very briefly in the field (three days or less), clean off soil in the field with the Maus cleaner/loader — and then immediately place the beets into ‘stacker piles’ for long-term storage.”

    The concept being tested, Kalso explains, is whether moving the beets within that three-day period would be soon enough so that they wouldn’t enter the “rest-storage” phase.  So far, that seems to be the case.  There were no deterioration issues last year, and the company is confident the story will be the same this storage period.  During the 2010/11 processing campaign, recovery of the stacker piles was intentionally delayed until mid-January since the piles were storing so well.  As in 2010, “we have temperature sensors in both stacked piles (i.e., Sandusky and Dover), so we’re watching temperatures very closely,” Kalso notes regarding this year’s project.  (For comparison purposes, conventional piles have been “wired” as well.)  He adds that most of the 2011 beets ended up being stacked within 24 to 36 hours after being harvested, so they’re well within that three-day window.

    The Sandusky stacking operation has loaded out field beets from the Ruth and Ubly vicinities, utilizing a Maus owned by growers Chris Guza and Les and Doug Volmering.  This grower group also hauls the cleaned beets from their fields to the stacker piler at Sandusky, averaging about 40 tons per load.

    The Dover operation has utilized a commercial trucking company contracted by Michigan Sugar.  One reason for doing so was the consistency of that fleet.  “Because the dumping parts of their trucks were similar, we could match our conveyor configuration to fit; if we have a fleet of 25 trucks, they’re all the same,” Kalso notes.  The Ontario fleet averaged about 43 tons per load.  Dover growers paid the freight to get their beets from the field to the piling site.

    The 2011 stacking operation west of Bay City relied on grower Allen Moore, owner of a Maus, who coordinated with several other area growers.

    “The biggest [potential bottleneck] is not the stacker,” Kalso adds.  “It’s trucks.  You need a lot of trucks, because the Maus has capacity to clean and load up to 400-500 tons per hour.”

Michigan Sugar’s plan is to conduct the stacked pile research project for one more year on a limited basis, do more intensive storage studies — and then expand the Maus/stacker concept to other piling sites, assuming all signs are favorable.

    The expansion is limited by not knowing the sustainability of the stacking and storage of the beets, Kalso says.  “Quite a few growers are interested in buying a Maus; but we don’t want to go ‘too big too fast’ right now.  If for some reason the beets don’t store well, we don’t want to be sitting with a lot of problems in the piles.”  He emphasizes, though, that to date the stacked beets have stored just as well as the conventionally piled ones.  “But that’s the reason we’re watching internal pile temperatures so closely,” he points out.

    Michigan had a wet fall in 2011 — which favors in-field cleaning.  “When they sit for a day or two, the soil dries a bit and comes off easier,” Kalso notes.  “That’s a nice advantage since that dirt is not being trucked to the piling site; it stays in the field. We were very pleased with how that worked this fall.”

A Ropa Maus unit cleans beets and loads a truck at field's edge. Photo: Keith Kalso

    In the end, Kalso says the field-cleaned/stacking approach promises several benefits for both grower and the sugar cooperative? 

    From the grower’s vantage point, it boils down to:

• Reducing freight cost due to less dirt/mud being hauled.
• Shorter lines at the piling yard.
• No cross-contamination of soil at the piler.
• Less or no road mud.
• Perhaps a need for fewer trucks.
• A partial “disconnect” between digging and piling, so one can harvest at his own desired pace.
• The Maus adjusts better than do pilers to field conditions for cleaning.

    From the company standpoint, stacking’s benefits would include:

• Shorter lines at the piling yard.
• Tare dirt remains in the field.
• The Maus is gentler on the beets compared to standard pilers.
• Less labor is required to operate stackers.
• Grower shares responsibility for cleaning the crop.
• Converting older pilers to stackers is less expensive than purchasing new pilers.

    So are there any downsides to this method of cleaning and piling sugarbeets.  Yes, a few.  For the grower, field piles need to be accessible — regardless of what the weather is like.  Also, the field’s tare soil ends up in a more-concentrated area.  Finally, company ag management controls the schedule, so that can translate into less flexibility.

    From the company’s standpoint, the field cleaning/stacking process does require intense management.  If beets freeze before going into the pile, that would cause problems.  And finally, there’s the pressure to move those beets into the pile within that three-day window.

    To date, though, the positives have far outweighed any negatives, Kalso reiterates.  One more year of research should go a long way toward determining if indeed this method of cleaning and storing sugarbeets becomes a widespread practice for Michigan Sugar Company and its growers. -- Don Lilleboe

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