Produce ethanol, beef for more profit
South Dakota State University research suggests there’s an economic opportunity for corn producers willing to background beef calves.
The numbers, based on regional data, suggest corn farmers in South Dakota and neighboring states can produce 383 gallons of ethanol per acre from their corn crop, as well as backgrounding 760 pounds of beef. The linked production system is also better for soil sustainability and will help the producer’s bottom line by saving on fertilizer costs.
• Backgrounding calves is an opportunity for corn growers.
• It’s possible to make more money per acre with beef in the mix.
• The integrated mix produces both ethanol and meat.
The integrated model includes harvesting some corn stover to mix with the distillers grains produced during the process of making ethanol and feeding that to those cattle, then returning the manure from the cattle operation to fields.
The SDSU analysis suggests producers will make more money, remove fewer nutrients and still return nearly as much carbon to the land, if they adopt such an integrated grain, ethanol and livestock production system. The model doesn’t take into account the additional corn beef cattle will consume in the feedlot before going on to slaughter, however.
“Integrated farming systems are not a new concept for farmers, but having the data to support the positive impact of growing corn for livestock and ethanol validates what farmers have known all along: Efficiencies are gained through life cycle systems,” says David Fremark, president of the South Dakota Corn Utilization Council, which helped fund the study. “As corn farmers continually look for ways to increase soil sustainability while achieving greater productivity, raising corn for meat and fuel is a viable and environmentally enhancing solution.”
Manure returns nutrients
SDSU scientists looked at the ethanol production process to see what is being diverted from livestock and to determine whether it could be replaced. Ethanol production doesn’t divert much nitrogen, phosphorus or potassium, since virtually all of those nutrients remain in the distillers grains, the coproduct of ethanol production. That means those nutrients remain available to livestock when the distillers grains are used in livestock rations. About 60% to 90% of those nutrients can then be returned to the land in the manure.
But ethanol production does divert a substantial portion of carbon away from livestock production. The question then becomes whether that carbon can be replaced in livestock diets.
Corn stover — the stalks, leaves and cobs left over after the grain is harvested — contains carbon and can be blended with nutrient-rich distillers grains to make an ideal ration.
Distillers grains by itself is so rich in nutrients that several SDSU researchers in past years have looked at locally available fibrous residues such as corn stover as a means of diluting the high energy and protein content in distillers grains. The integrated model the SDSU scientists propose would use that corn stover and distillers grains mix as a ration for backgrounding calves.
During backgrounding — when steers are fed to increase their weights from about 450 to 750 pounds, in this case — the animals can be fed a diet consisting of corn stover (33%), hay (22%), shelled corn (15%) and distillers grains (30%).
The SDSU researchers say the regional average of 162 bushels of corn per acre produces about 437 gallons of ethanol per acre, as well as 2,920 pounds of dry distillers grains with solubles, or DDGS, per acre.
In non-integrated systems — those in which the corn is sold to the ethanol plant, no livestock are figured into the equation and corn stover is returned to the field — the partial profit from growing that corn to make ethanol is $139 an acre. The soil carbon returned to the soil amounts to 6,920 pounds per acre, and farmers the following year can expect to apply about 146 pounds of nitrogen and 62 pounds of phosphorus fertilizer to the soil to maintain fertility.
In the integrated system, the same corn yield would produce 383 gallons of ethanol. But because the operation is designed to ultimately help produce 760 pounds of beef per acre, the partial profit per acre rises to $278. In the integrated system, 60% of the corn stover would be harvested, mixed with DDGS, and fed as a backgrounding ration to calves. Manure from the cattle operation would then be applied to the land, returning 5,629 pounds of carbon per acre. In addition, the manure would lower the required fertilizer demands to 57.5 pounds of nitrogen and 24 pounds of phosphorus per acre. Returning the manure to the land and leaving a portion of the stover in the field also helps maintain soil quality.
Some farmers already are using such an integrated system for producing both meat and ethanol. It will make better use of the nation’s corn crop if more farmers adopted such a model, the SDSU scientists say.
SDSU agronomist Gregg Carlson and soil biogeochemist Dave Clay of the SDSU Plant Science Department, Extension beef specialist Cody Wright of the SDSU Department of Animal and Range Sciences, and Kurt Reitsma, coordinator of the SDSU Carbon Project, collaborated on the study.
Nixon is a writer with SDSU AgBio Communications.
This article published in the July, 2010 edition of DAKOTA FARMER.