ONTARIO - Researchers Clint Shock and Erik Feibert at Oregon State University's Malheur Experiment Station, say they have identified a way local agricultural producers and processors can meet each others' needs with what used to be waste materials.
The high concentration of farming and agricultural processing in the Ontario-Boise area is a shell game of sorts, according to Shock. A beef cattle feedlot gets culled French fries, and low-feed-value potato sludge, from the company that processes the fries. The material is used in cattle feed.
Another local company gets small and otherwise unsaleable culled onions from packing sheds and distills the small amount of oil for sale as a value-added product.
But in both cases, there are still leftovers.
The OSU scientists believe they have found a way of utilizing those secondary waste materials and reducing local farmers' fertilization costs.
The waste products complement each other, Feibert explained. Potato sludge, consisting mainly of finely pulverized peels and waste water, is a thick paste the texture of gelatin, while onion sludge is mostly liquid.
Onion sludge is difficult to spread. But combining it with potato sludge produces a consistency easily distributed by a standard manure spreader, or "flinger."
"By weight, the processing waste stream in the area is about 60 percent potato and 40 percent onion, so we have about the perfect mixture available," Feibert said.
They've seen what the mixture can do.
"This was almost useless, eroded, hard-pan soil before the Experiment Station added a massive (about 50 tons per acre ) amendment of potato and onion sludge," Shock said, referring to land on the station where experimental corn grew last summer.
Corn fertilized with the combination of potato and onion sludge yielded 204 pounds per acre, compared to 111 pounds per acre for corn on nearby unfertilized ground. Corn fertilized with potato sludge alone yielded 183 pounds per acre, the same as corn fertilized with 200 pounds per acre of nitrogen, the commercial fertilizer farmers in the area commonly use.
Fertilizing corn with nitrogen, at the standard rate of 200 pounds per acre, costs a grower $50 to $60 an acre including delivery, Shock said.
The sludge, on the other hand, is delivered and spread without charge to the grower - at the moment. But it will have a market value in the future, he predicts.
"This is a pretty good example of companies trying to be creative with materials they can't use," said Shock.
According to the OSU scientist, studies in 1996 by Lynn Jenson, a Malheur County Extension agent, indicate that about 20 percent of the available nitrogen in the sludge mixture is released the first year.
OSU researchers are still experimenting with various rates of application to identify the optimal sludge fertilization rate for corn.
Companies collaborating with OSU on the research include Beef Northwest, a cattle feedlot in Nyssa, Ore., and OreIda, of Ontario, Ore., which sells French fries and other frozen potato products.