While most of the focus on containment for fertilizer starts with the ground to control runoff and seepage, covers also play an important role when you can’t use enclosed tanks and containers. Open bunkers and concrete pads can serve as temporary or permanent fertilizer storage with the addition of the right cover. Even permanent fixtures like silos and open top tanks need covers to prevent nitrogen loss to the atmosphere that contributes to greenhouse gases. Make sure you’re using the right covers for your fertilizer with these considerations.
Biogas Digesters
Biogas digesters are some of the most challenging manure containment systems, yet they’re also highly valuable. A well-constructed digester takes in raw manure slurry and produces both a valuable liquid fertilizer and methane gas to use for heating or power generation. On-farm biogas digesters require special design because they hold flammable gas, but they’re a powerful addition that can close a waste loop that causes environmental damage and added disposal costs. Since the covers on these digesters stretch as the gas accumulates inside, they’re under a lot of tension and must resist ripping and tearing. Reinforced flexible covers are the best option since they have the tensile strength to stretch without bursting open.
Manure Lagoons
Manure lagoons aren’t designed specifically to generate methane, but they still create it as a byproduct. This means that they’re best covered until the slurry can be reused as a fertilizer on the farm or elsewhere. Covers for manure lagoons will stretch just like those on biogas digesters, so they should still meet the same specifications to prevent ruptures that release concentrated gas. Make sure to plan for rainwater accumulation over the covers when they’re not highly inflated so that the weight of the water can’t push the material down and disturb it.
Preventing Accidents and Animal Access
Any open fertilizer pile or container should have a cover when it’s not in use to prevent accidental access. Humans or animals that fall into a pile of liquid or dry fertilizer often suffer serious injuries, or worse, before they’re found and rescued. Covers don’t need to be completely access-resistant to prevent these accidents. If you suspect there may be intentional attempts to access the fertilizer, you will need more secure covers that can’t be pulled or lifted away.
Flexible vs Rigid Covers
Silos and large, open-topped tanks are often capped with rigid metal covers rather than flexible ones. This is recommended when it’s necessary to walk over the top of the tank or when a structure is so tall it’s impractical to visually inspect the cover on a regular basis. For shorter tanks and bunkers, a tension system and a flexible cover is often a better choice. These covers are easier to remove and replace when working on the container or refilling it. They’re also less likely to become damaged by gas accumulation or pressure changes. Check state regulations before deciding on any particular type of cover for custom-built fertilizer silos and bunkers
BTL Liners doesn’t just carry the liners you’ll need for fertilizer containment at the ground level. We also provide durable cover materials that can handle fertilizer storage requirements and more. Check out our selection or contact our team for custom recommendations based on your project.