07/22/08 Straw residue may be too valuable to harvest for biofuel

Farm and Ranch July 22, 2008 The wheat industry has been supportive of the development of cellulosic ethanol as a market for straw, which could provide another income stream for growers. But Ann Kennedy, a USDA-Agricultural Research Service soil scientist, says Palouse wheat growers should think twice before harvesting crop residue for biofuel production. Kennedy has conducted research showing that you need about one ton of straw an acre in the Palouse to increase organic matter in the soil and that can be done with a no-till or a one-pass system. She says in many cases there is straw in excess of that one ton an acre that could be used for biofuel, however; Kennedy: "You kind of have to do the math on that because it may be more expensive to bale it off and use it for biofuels just because of the amount of cellulose in wheat straw versus the amount of fuel you get off. I would hope people would think first of the organic matter input because that is probably the most important product of the residue and then secondly think about the biofuel value." Kennedy also says that extra residue provides surface cover and that layer is extremely important if low-residue crops are in the rotation. She hypothesizes that in lower rainfall areas the amount of straw needed to build organic matter would increase. I'm Bob Hoff and that's the Northwest Farm and Ranch Report on the Northwest Ag Information Network.