Selecting the right silage cover material is still just part of designing the total cover system. Weights that keep the cover from rising or blowing away are just as important are the barrier itself. While there are many low cost or free materials around the farm to reuse for a small silage pile, most farmers will need to invest in some kind of specialty equipment for large, silage silos. The wrong weight material could tear the cover or at least cause wear over time. There’s also the risk of the weight being too light and sliding or blowing off in a bad storm. Make sure you’re using the right weights over your silage covers by exploring your options.
Tires are one of the original materials for holding down any kind of tarp on a farm, including a silage cover. While tires are often free or low cost and easy to source, they do cause a few issues for the environment and the cover material. First, whole tires tend to trap water and breed mosquitoes or cause flooding that seeps into the silage pile. Rats also tend to move in and then chew into the silage pile below. Using tire sidewalls cut free from the tread can prevent all of these problems, but they cost either money or labor. Damaged whole or cut tires expose steel belting that can tear even the strongest silage covers. They work well if you can find affordable and clean sidewalls in enough numbers to cover the entire surface.
Solid rubber mats are often made from recycled tires to weigh down silage covers without the risks of standing water or pest attraction. They’re usually designed with perforations to let water drain through and over the impermeable cover below. Don’t expect these mats to be able to offer waterproofing ability since they’ll shift and move as the silage pile settles. They are good for protecting the cover from damage when humans or cattle step onto the pile surface. Due to the amount of material needed to cover the entire surface of a silage pile, rubber mats tend to cost more than other manufactured weights.
Rubber hoses run over the silage cover at intervals may not look heavy enough to serve as weights. Yet, when they’re properly sized and spaced, these hose systems are some of the most effective ways to keep silage covers weighted year-round. They hook up to your farm plumbing system so you can automatically fill and drain them as needed. It’s easy to move the empty hoses out of the way or back into place in seconds with only a fraction of the effort needed to replace rubber mats or tires. They are costly but can cost less than trimmed tires due to the need for fewer hoses. If you plan to store silage primarily over the winter rather than for summer droughts, you may need a hose system that hooks up to your hot water supply or with integrated heating wires.
The oldest form of silage cover is soil. Some of the first farmers in the 19th century to experiment with fermentation simply piled soil directly over the silage with no barrier between. While today’s farmers know they need an impermeable cover first, soil can still serve as a very protective, secondary cover for the pile. It offers the most UV blocking protection and is heavier per square inch than many other materials. Unfortunately, that weight can also backfire and cause too much settling in the pile. If plants sprout up in the soil, the roots also run the risk of penetrating the cover below and allowing oxygen and water in. Balance the low cost of using soil with the need to apply weed control sprays that must be feed-safe due to its close proximity to the silage below.
Gravel or Rocks
Some farmers experiment with gravel or larger rocks known as rip rap for weighting silage covers. While these materials are certainly heavy enough and are often free or low cost, they’re too rough and sharp for most covers. It’s fine for temporary use, when it’s the only option, but if you’re trying to optimize production and make your covers last as long as possible to reduce costs, find a better weighting material as soon as possible.
As you can see, most of the free or low-cost weight materials are at least somewhat appropriate for silage covers. To get the most out of your cover and to ensure the tightest fit for oxygen control, stick with a system that’s designed specifically for silage use. No matter which weight you choose, we’re happy to help you find a matching cover that can handle your weight choice, here at BTL Liners.