Why Silage Clamp Losses Cost More in 2026 Than Most Farms Realise
Key takeaways
· Total dry matter losses from field to feedout can reach 40% of what was harvested, and most farms have never accurately costed what that represents.
· Fertiliser and input costs remain well above pre-2022 levels, meaning every tonne of silage lost to spoilage is more expensive to replace than it used to be.
· The majority of in-clamp losses come from the same predictable causes: poor compaction, inadequate sealing, and ageing infrastructure.
· Good clamp management is now a commercial decision, not just a technical one.
Silage losses have always been part of farming. For most operations, they have been quietly accepted: a percentage here, a bit of spoilage there, never clearly costed. That approach is getting increasingly hard to justify in 2026.
Input costs remain well above pre-2022 levels. Fertiliser prices, though more stable than during the energy crisis peak, are still elevated and facing upward pressure from new carbon border regulations and ongoing geopolitical uncertainty. The 2025 growing season was one of the driest in recent memory, leaving many farms heading into this year with tighter silage stocks than they would like. The financial headroom that once absorbed operational inefficiencies has narrowed considerably.
In that environment, wasted forage is no longer a minor problem. It is a margin problem. And for many farms, the scale of those losses is larger and more expensive than the business has ever stopped to calculate.
Where Losses Actually Happen: Field to Clamp to Feedout
Losses do not happen at a single point. They accumulate across every stage of the silage-making process, and the total can be significant.
At harvest and wilting, dry matter starts to be lost the moment the crop is cut. Respiration continues until the ensiling process shuts it down, so delays in wilting or cutting at the wrong stage of maturity extend this window and increase field losses.
During fermentation, some loss is inevitable. But where fermentation is poor (through insufficient compaction, oxygen infiltration, or high moisture content) the wrong bacteria take over, burning through dry matter and degrading energy and protein in the process.
In storage, oxygen infiltrating through poorly sealed sheets or air pockets left by inadequate compaction drives aerobic spoilage. This is visible as heating, mould, and dark material that livestock will refuse. These losses continue for as long as the clamp is imperfectly sealed.
At feedout, a face that is too wide for the rate of removal exposes a large surface area to oxygen each day, and silage that has partially heated reduces intake and nutritional value even when animals do consume it.
Research suggests total dry matter losses from mowing to feeding can range from 5% to 40% of what was originally harvested, with the higher end far more common on farms with older infrastructure than many would expect.
Why Small Inefficiencies Become Expensive in a High-Cost Market
The numbers look different when you factor in what it costs to produce forage in 2026. Every tonne of silage represents fertiliser, fuel, contractor time, and the management overhead of covering and monitoring a clamp. Fertiliser costs, which averaged around £217 per tonne of ammonium nitrate before 2022, are still running well above that baseline. With the UK's Carbon Border Adjustment Mechanism due in 2027, the long-term direction is clear.
Put simply: a 15% storage loss on a 1,000 tonne clamp is 150 tonnes of silage that was grown, harvested, and stored, then lost before it reached an animal. At current bought-in forage prices, reported as high as £65 per tonne for good grass silage, that is a cost most businesses would not accept in any other part of their operation.
The point is not that every farm is losing 15%. It is that most farms do not actually know what they are losing. You cannot manage what you do not measure, and losses that feel abstract at harvest feel very real when you are buying in forage to fill a gap in February.
The 2025 drought made this clear. Many farms entered winter with forage shortfalls not just because of poor growing conditions, but because in-clamp losses had quietly eroded what was there.
The Operational Factors That Drive Spoilage and Waste
Most silage losses are predictable. They tend to cluster around the same operational factors.
Poor compaction is the single biggest driver. Insufficient compaction leaves air pockets that oxygen can occupy, creating the conditions for aerobic spoilage. This is particularly acute at the shoulders and edges of the clamp, where traditional vertical-walled designs make it difficult for machinery to work right to the edge. A sloping wall design addresses this directly, reducing the shoulder losses that vertical walls make almost inevitable.
Inadequate sealing is the second major factor. High oxygen barrier films significantly outperform standard polyethylene sheets in limiting surface losses. Corners and joins are the most vulnerable points, and any compromise there creates a pathway for ongoing spoilage throughout the storage period.
Clamp age and condition is an increasingly significant issue. Many clamps in use across the UK are 40 or more years old, built for farm operations and machinery that bear little resemblance to today's. Cracks in the base and walls, degraded drainage, and failing effluent systems all compromise silage quality and create compliance risk alongside it.
What Farms Can Do to Protect Value
Invest in clamp design that enables good compaction. The geometry of the clamp determines how effectively you can exclude air from the silage mass. Getting this right at design stage eliminates a structural source of loss that operational management cannot compensate for later.
Use a true oxygen barrier film. Not all silage sheets perform the same. A high oxygen barrier film, correctly applied with proper shoulder coverage and weighting, is one of the most cost-effective investments available in silage quality.
Analyse your silage and cost your losses. An annual silage analysis gives you the nutritional picture. Tracking how much dry matter went in versus what was fed out gives you the commercial picture. Many farms that have done this for the first time have been surprised by the results.
Plan clamp upgrades before the season, not during it. With SSAFO compliance requirements tightening and the Environment Agency increasingly active in enforcement, the cost of deferring infrastructure decisions is rising.
Good Clamp Management Is Now a Margin Strategy
Silage storage has traditionally been framed as a technical issue. In 2026, it is also a straightforward commercial one. When inputs are expensive, wasted forage is no longer a rounding error. The real cost of poor storage shows up long after harvest, in bought-in feed bills and forage gaps that could have been avoided.
The farms best placed to absorb current market pressures are the ones treating clamp management as a margin strategy, not just an infrastructure obligation.
If you would like to discuss how your existing clamp is performing, or explore what an upgrade could do for your storage efficiency, get in touch with the Silostop Agri team.
ARK Agri specialises in the design and installation of silage clamps across the UK, supplying sloping wall and vertical wall systems alongside industry-leading silage protection products including Silostop oxygen barrier films and Secure Covers clamp netting.