Custom harvesters working for Abengoa Bioenergy package 50% of the available stover in 3 x 4’ bales.
Bruce Nelson sees custom-baling corn stover for cellulosic ethanol plants as a great opportunity for young farmers willing to put in long hours.
“It’s probably the least glamorous thing you’ll ever do,” he says. “But if you have some ambition and you’re ready to bear down and do some work, it’s a great way to get started in farming.”
This Emmetsburg, IA, corn grower and custom harvester has baled and transported corn-crop residue for Poet-DSM Advanced Biofuels’ Project Liberty the past two years. The work – especially hauling bales to the company’s storage yard in winter – has been harder than he expected.
“We learned a lot the first year – where to stack them, where not to stack them, those types of things,” says Nelson. “And then this year we still made a few mistakes, but we got a lot better.”
But equipment and procedure refinements are needed, he says, to enable farmers and custom operators to efficiently supply the massive amounts of biomass that will be needed to feed hungry ethanol plants.
“I bet in about five years we’ll look back at this experience and laugh at ourselves for the way we were trying to do it,” says Nelson.
The planned plants include Poet-DSM’s at Emmetsburg and the Abengoa Bioenergy facility in Hugoton, KS, both scheduled to open late next year. When at capacity, the Poet-DSM facility will process about 280,000 dry tons of stover annually; the Abengoa plant, 320,000 dry tons of stover, wheat straw and switchgrass. Custom operators have already harvested biomass at both locations, and company officials say more help will be needed.
The companies have strict stover collection guidelines that must be followed. Poet-DSM only wants residue that comes through combines – mostly cobs, husks and leaves. No raking or shredding is permitted.
“We ask a farmer to disengage the chopper or spreader on the back of the combine, lay a windrow down and come back with a second pass and collect it with a baler,” explains Adam Wirt, Poet’s biomass manager.
Cornfields in that area average about 4 dry tons of residue per acre, and Poet’s collection method removes about a ton. Four years of work with USDA and Iowa State University identified that as a sustainable stover removal rate, says Wirt.
Large square bales or net-wrapped round bales are accepted. Round bales must be 5’ wide and about 5’8” tall. Square-bale size requirements are less stringent, but 3 x 4 x 8’ bales are preferred.
Poet-DSM paid 85 farmers for 56,000 tons of dry stover in 2010 and ramped up to 61,000 tons from about 100 farmers last year.
“We might increase that number slightly in 2012, leading up to the 2013 harvest, where we could be looking to do about 250,000 tons,” Wirt reports.
Most of the farmers also sell grain to Poet for its corn ethanol plant at the same location, and a majority harvest and haul the stover themselves. So far, 25-30% of the supply has been handled by custom operators hired by farmers, he estimates.
In Kansas, Abengoa Bioenergy does the hiring, and to date only two custom harvesters – from Ohio and Oregon – have been used. They baled and delivered 12,000 tons last fall, and will do more this year, along with 5,000-7,000 acres of wheat straw.
“As we scale up this process and learn, there’s a very large potential for the need for custom forage harvesting,” says Tom Robb, manager of institutional relations.
Brad Niehues, biomass field manager, says the company worked with Natural Resources Conservation Service (NRCS) personnel to determine how much stover could be removed from fields and still protect soils from wind erosion.
“It varies by soil type, but I would say, on average, we’re taking 50% of what’s out there,” says Niehues.
Abengoa wants 3 x 4’ square bales, and for corn stover, mostly corn leaves and husks, though the company also takes some cobs and stalk pieces. A rake or shredder is used prior to baling, but the company is looking at alternatives that will gather the desired material with less dirt.
“We’re evaluating some pieces of equipment that really could help with this,” says Niehues. “They’re not built yet, but the concept is there.”
Custom harvesters working for Abengoa will have to follow NRCS guidelines and meet the company’s quality standards, Robb emphasizes. Some contracts likely will cover baling and delivery; in other cases the two operations will be contracted separately.
Nelson farms with his dad and uncle, and they sell stover to Poet from all their corn acres. The custom stover harvesting business he runs with a friend serves a handful of local farmers who don’t have the labor or equipment to do the work themselves.
He says baling 1 ton/acre for Poet is a lot different from traditional corn-stover harvesting. The windrows are small, and some husks and cobs are left on the ground because the company wants clean stover.
“You drive forever to make a bale,” says Nelson. “Poet is telling us to raise our pickups, and the farmers are telling us to lower them. We’re kind of in the middle because we want to do it right. It’s a real challenge.”
Baling takes place shortly after grain harvest, and bales are stacked at field edges for wintertime delivery. Transporting round bales is “the biggest obstacle that comes with this,” says Nelson. Bales freeze to the ground and to each other, and some break when moved.
Better round-bale moving equipment is needed, he says. “There’s a lot out there, but to be quite honest, it’s not where it needs to be to do mass production in the round bale.”
He considered switching to big square balers to simplify hauling, but they’re more expensive and require bigger tractors. A lack of square-baler dealers in the area is another hindrance Nelson mentions.
Interested harvesters can contact Poet Biorefining – Emmetsburg Commodities Team at 712-852-8700 or Niehues at 620-544-7780.