A trommel screen separates organic material based on size. The organic material is placed in the large hopper using a front end loader, and is then separated by size.
Composting manure offers new revenue stream
For cattle producers, what goes into the animal and what comes out are two issues that have to be managed. On the tail end, some producers are looking to the enterprise value of composting manure.
"Manure management is an opportunity to make money," says Craig Coker, owner of Coker Composting and Consulting in Virginia. "Composting manure can be a significant source of revenue, but economic viability needs to be carefully researched."
In addition to the potential extra income, composting offers an environmentally friendly addition to your business since it recycles manure into a natural fertilizer.
That environmental component was partly why Darin Mann and his father, Kent, decided to expand their composting facility at their dairy replacement heifer feedlot near Parma, Idaho. M&M Feedlot is home to 12,000 replacement dairy heifers, so manure management is a big issue.
Composting has not only provided a value-added enterprise, it also has improved animal health and pest control and offered aesthetic benefits. With pens scraped weekly, flies are not an issue and there is little to no odor coming from the facility. Composting is also part of the reason the Manns were named winners of the National Cattlemen’s Beef Association’s Region V Environmental Stewardship Award.
Composting has become a significant part of the Manns’ family farming business. Four years ago, they cleared out an additional 18 acres to increase compost production. Besides selling compost to area farmers, they also started selling into home and garden retailers in the area. Now, almost 100% of the manure produced in the feedlot is composted on-site.
Although the compost process takes months to complete, there are benefits beyond the environmental aspect. For instance, compost is easier to store and handle compared to manure, since the moisture has been removed, so farmers and other consumers may prefer it over manure.
Most of the compost from M&M Feedlot can be cost-effectively shipped to farmers and retailers in a 30-mile radius. This past summer, the Manns charged $12.50 per ton, but Darin says they will be raising the price to $13.50 per ton due to increased fuel cost. The Manns set the price on a yearly basis, and they also provide spreaders for farmers to use.
Equipment needs. Composting basically requires the ability to transport the manure to an area where it can be spread out and turned regularly during the process, which has to reach high enough internal temperatures to kill pathogens and weed seed. There is both a science and an art to the process in terms of windrow spacing and mixing of manure with other elements.
While it can be done with a front end loader, equipment that is specially designed to do a more thorough job may be a better option.
At M&M Feedlot, manure is dumped into windrows that are 6' tall, 16' wide and an average 800' in length. Once the windrows are constructed, it takes approximately 120 days for the composting process to be completed, depending on temperatures. To efficiently turn and work the compost, the Manns use a drum-style turner that is pulled by a tractor over the windrows, mixing them thoroughly.
"Mechanical turners provide more consistent pathogen and weed-seed kill and rapid temperature rise," says Jeff Bradley, an applications engineer with Vermeer Corporation. "These help to reduce cycle times, allowing for more compost to be produced annually and maximizing the amount of oxygen introduced."
When comparing equipment to purchase, he says, be sure to look at total cost of ownership, not just the purchase price. In terms of mechanical turners, Bradley explains that there are two options: drum-style turners and elevating-face turners.
Space dictates the choice. When space is not an issue, many owners of compost sites prefer drum-style turners. These are used only in windrow configurations, with the machine straddling the windrow. The turner features a horizontal steel drum with paddles that mix air into the windrow. It can be either PTO-driven or self-propelled.
Elevating-face turners can be used for regular windrows or a continuous-stack configuration where the windrows overlap, which might be ideal where space is a limiting factor. This equipment uses a combination of paddles and teeth to lift and tumble the material up the face of the machine; the organic material is discharged from the rear or side of the machine. Elevating-face turners require 30% to 50% less horsepower per cubic yard compared to drum-style technology, Bradley says.
Depending on the type of compost product you are producing, a trommel screen may be necessary to separate the organic material based on size. The organic material is placed in the large hopper using a front end loader, and is then separated by size.
"Remember, making compost is manufacturing a product," Coker says. "So there are expenses and the product is a commodity."
Develop a business plan and a budget to get the most from this type of enterprise.
- November 2011