New York dairy producers may be among the first in the country to deal with a new regulation source: the tires they use to secure the plastic sheeting and film that covers their silage bunkers and piles.
Agricultural groups – including the New York Farm Bureau, Northeast Dairy Producers Association, and PRO-DAIRY at Cornell University – have been advocating for adjustments to regulations on waste tires to protect their on-farm use for silage-cover anchors. While some concessions have been made, farmers still are being required to make changes to the practice.
The New York State Department of Environmental Conservation (DEC) issued an Enforcement Discretion Letter in March 2018. The letter provides for an additional year for farmers to comply with new requirements to continue using tires to cover silage tarps, which are described in a Beneficial Use Determination (BUD) issued by the DEC.
The regulations require that farmers use only 0.25 passenger tire equivalent per square foot of bunker silo coverage; excess tires beyond these limits that are not used within 18 months must be removed from the farm. Tires must be cut in half or have holes drilled in them for water drainage.
Concern about tires on farms stems from issues of standing water that accumulates in them. The water can serve as mosquito breeding grounds that could lead to the spread of viruses like Zika and the West Nile virus.
But farmers have concerns of their own, including the fact that slicing or stamping tires that contain metal wires in the treads or side walls (most car tires do) produces hazards to humans and animals. Workers modifying the tires and handling them afterward are at risking of lacerations from protruding wires, and loose metal shards can contribute to dangerous hardware disease in cattle. Exposed metal also can slice plastic covering, causing silage to spoil.
Disposing of excess tires is another challenge. The New York regulations prohibit on-farm burial or burning of excess tires, and landfills and other waste handlers willing to accept them vary by region.
The issue leaves many producers searching for alternatives to full-casing tires to secure silage plastic. Some possible options include:
- Sidewall disks – These disks – described in a helpful publication from Penn State University Extension – are derived from bias-ply truck tires, which contain nylon belts instead of the steel belts of radial-ply tires. They are basically scraps leftover when sections of the sidewall have been removed for other manufacturing purposes. Sidewall disks often have holes punched in them, which reduces the water-holding concern, but makes them lighter weight. According to the Penn State document, they only provide about half as much weight as full-casing auto tires. But, that lighter weight makes them more user-friendly to human handlers, and their flat shape means they are more easily stored on pallets when not in use.
- Heavy equipment tire beads – Penn State Extension also describes this alternative, which are the rigid steel bead portion of large agricultural or earthmoving equipment tires. With a diameter of 2 to 4 feet and a weight of 25 to 75 pounds, they can be more challenging to handle, but provide excellent coverage and weight when in place. Because they come from bias-ply tires, they do not have protruding wires to cause injuries or plastic punctures.
- Cow mats – If you can find them, recycled rubber cow mats or mattresses are an excellent alternative to tires. They can be placed side-by-side for thorough coverage, and are easily stacked and stored on pallets.
- Sand bags – Anchoring the edges and sometimes the full surface of silo plastic with sandbags is a sometimes-employed practice. While usually readily available, this can be a more costly and messy option because sandbags tend to break over time, and need to be cleaned up and replaced frequently.
- Bulk lime screenings – Some producers use bulk lime to anchor the ends of silo plastic, then still use tires or sidewalls to seal seams across the pile or bunker, and to hold down the cut edge at the feeding face. This requires fewer tires, but you also run the risk of unbalancing your ration if some of the lime is scooped up with the silage.
- Compost or separated manure solids – Another interesting concept is covering plastic or film with a layer of compost or separated manure solids if those products are elements of the farming operation. If the unit will be covered for several months, the surface even can be seeded with a cover crop like rye or triticale. A concern with using these materials near the herd’s feed source is spreading vertically transmitted diseases like salmonella and Johne’s Disease.
Clearly, no alternative to tires is perfect, and the choice will differ for every farm based on cost, labor, available equipment and local resources. University of Wisconsin Extension Engineer Brian Holmes maintains that what currently is not an option is discontinuing the use of plastic or film as the best covering to prevent spoilage. He said covering silage with such alternatives as molasses, sawdust or sod – or even putting a roof over it – have proven no better at preventing spoilage than simply leaving the silage completely exposed.
Some producers have chosen instead to abandon bunker and pile storage altogether and switch to bagging silage, which is an expanding option due to the advent of larger baggers. And for even more intriguing food for thought, check out some alternatives that are in use in Europe – examples of silage “balers” in Switzerland and Norway.