Prairie fuel – A new market for prairie hay

By Dan Looker

ANKENY, Iowa (IAWA) – Iowa farmers who plant prairie strips may soon have a new source of revenue for harvesting them.

This spring, St. Louis-based Roeslein Alternative Energy finalized an $80-million USDA contract under the department’s Climate Smart Commodities program, which will allow the company to compensate farmers who harvest prairie hay. That biomass will be mixed with cattle or hog manure in digesters that produce methane gas.

The company is already working with large hog producers, including eight northern Missouri hog farms owned by Smithfield Foods, said spokesman Bandon Butler. Methane from 83 manure lagoons produced 800,000 decatherms of fuel last year – that fuel was injected into the national natural gas pipeline. The project, called Horizon I, has even more manure-to-fuel biogas production in Utah.

The new Iowa project, dubbed Horizon II, aims to increase green fuel derived from manure.

“We can generate more methane than we could with manure alone,” said Butler.

Bryan Sievers and his family have been doing something similar for about a decade on their Stockton, Iowa farm. Ten years ago, they started using a digester to make methane from their 2,400-head cattle feedlot. Six years ago, they started using a silage chopper to harvest cover crops, adding the cuttings to the digester daily.

They’ve applied what’s left from this process, called digestate, to their fields. In the past ten years, this nutrient-rich material has helped replace purchased fertilizer and has raised the organic matter in their fields from an average from grid sampling of 3.5% to about 5%, Sievers said.

 He now also works for Roeslein. The company has varying arrangements with livestock producers to set up third parties that build and run digesters, then sells the methane as renewable natural gas. The livestock farms are paid for either the manure going into the digesters or, if they provide the manure at no cost, they are compensated with digestate to be used as fertilizer.

Sievers envisions farmers harvesting prairie hay every two to three years to feed into digesters that will be located on Iowa hog, cattle and dairy farms.

“We think producers are going to be able to profitably produce prairie in targeted areas,” he said.