Farmers are far from limited in their options for storing fertilizer on site at the farm. Keeping large amounts of fertilizer on-site allows for immediate use when a deficiency is identified in a bare or planted crop field. It’s also the only way to make affordable bulk purchases rather than costly small-scale orders throughout the season. However, not all bulk fertilizer storage options offer the same benefits as others. Many of the most durable seeming silos and tanks are unfortunately the hardest to secure with secondary containment for spills. Compare and contrast the most popular bulk fertilizer storage selections based on their features and containment compatibility.
Concrete and Metal Silos
For storing dozens of tons of fertilizer at once, with as much security as possible, farmers often have to invest in permanent concrete or metal silos. Silos designed for storing grain or feed can be repurposed to store fertilizer, but only with thorough leak testing and the addition of containment with lined dikes. It’s often easier to implement secondary containment on new silos than on existing ones since it’s best to protect the soil below with an impermeable layer of geomembrane. Trying to roll out these flexible liners around an existing silo will only provide limited spill containment. Silos may be large and sturdy, but they’re often even more prone to developing leaks over time due to their size and construction methods.
Above Ground, Buried Metal and Concrete Tanks
When silos are too large but there’s still a generous volume of fertilizer to store for long periods, metal and concrete tanks are a popular option. Concrete tanks are usually pre-cast at this size rather than cast in place, but sometimes they’re also built from blocks in a covered bunker style. These tanks are often less prone to cracking and leaking than full-sized silos, but only during the first few years of use. They still require extensive containment and must be properly sized to contain 110% or more of the volume of the largest container. Buried tanks still pose leak risks because they’re even closer to ground water supplies. Surrounding a buried tank with a layer of geomembrane liner can control leak risks and extend the lifespan of the equipment.
For above-ground, plastic tanks are widely used by farmers who store small to medium amounts of fertilizer for short-term or long-term periods. Plastic nurse tanks are also widely used for transporting fertilizer around the farm and dispensing it in the fields. Plastic tanks are harder to patch and seal when damaged than concrete or metal, but it is possible to weld around cracks and holes. Since plastic tanks are just as likely as other materials to eventually develop leaks, they also deserve extensive secondary containment. Double walled plastic tanks are one way to achieve containment all in one unit. However, these tanks are far more expensive than single walled designs. You may find that building in-ground, secondary containment like lined basins, are more affordable than trying to upgrade to double walled storage tanks.
Dry Storage in Totes and Bags
The smallest amounts of fertilizer are generally stored in barns and sheds while packed into portable totes made from polymer fabrics. Naturally, this method will only work temporarily and can pose some safety risks. If you have buildings you intend to use for barrels, totes, and other smaller containers of fertilizer, try lining the floor of the entire storage area and adding curbs around the edges to keep any liquids or powders contained. Drains and sump systems can automatically remove spilled liquids to a safe secondary storage area until you can deal with them. Don’t assume that keeping totes or barrels inside a building is enough to protect your farm from the risks of fertilizer spills.
Mobile Tanks and Containers
Mobile tanks and containers, like nurse tanks, obviously can’t be protected with secondary containment at all times when traveling. However, there’s still a need for containment at spots where the tanks are filled or emptied. These loading areas are particularly prone to small spills that add up over time. Containment for a loading area is often more affordable than assumed because these zones are relatively small compared to storage spaces. Checking mobile tanks and containers for signs of leaks, before each refilling, is the best way to prevent leaks in the fields or roads.
Covered Pads and Piles
Manure and other organic fertilizer sources, such as blood meal and compost, are often stored in covered pads and piles. Larger, solid walled structures known as biodigesters are covered to keep methane and other gases in, as waste products break down into valuable fertilizer products. With covered pads, it’s possible to store purchased or self-produced manure for long periods without losing valuable materials. Since most organic fertilizers are particularly high in nitrogen, they can be more damaging to local waterways than other chemical fertilizers that aren’t ammonia based. Make sure these pads and piles feature both impermeable liners at the base and vapor-impermeable covers over the top for secure fertilizer containment.
All of these storage methods work for both liquid and granular/powdered fertilizer products, but their suitability for holding chemical fertilizers varies based on the material. Most metal tanks can hold fertilizers, thanks to the addition of the right protective coating. Plastic tanks are more versatile, but chemical resistance must still compatible between the fertilizer and the tank. Look for a highly chemical and corrosion resistant liner when designing secondary containment. We fabricate a variety of products that can handle exposure to the vast array of fertilizers here at BTL Liners. Consider our industry leading ArmorPro product line, capable of safely and reliably containing even the most difficult, corrosive chemicals.