It has been proven that silage cannot be stored effectively without the use of plastic silage sheets but there are options available that reduce plastic waste and ensure silage quality for New Zealand’s Farmers.
Silostop Orange is a single layer plastic High Oxygen Barrier silage sheet is one of these options and we explore why below.
The problem
Plastic plays an essential role in livestock production due to its durability, flexibility, and low cost. It has been estimated that globally 7 to 9 kg of plastic/cow/year are used in the dairy industry. This means that a herd of 1,000 cows can generate up to 9 tons of waste plastic per year.
This plastic is not always recycled (the actual recycling figure is understood to be below 10%). Which means a huge volume of plastic is buried, burned or left on farms around the world.
Silage sheets make up a small but important percent of this waste.
Plastic reduction
Conventional silage sheets (often thick black or black and white sheets) have been used to cover silage clamps for many years. These covers rely on the density of the plastic, its thicknesses, to create a limited oxygen barrier and are often made from lower quality materials.
Some farmers may choose to twin these conventional plastic sheets with a cling film layer doubling the plastic required. This is a low-cost high plastic waste option.
Technical silage sheets like Silostop Orange take a different approach, they use a thinner but more advanced mix of polymer compounds and EVOH resins which retain the useability of the conventional sheets but with significantly less material and a near perfect oxygen barrier.
What does this mean for plastic waste?
Work in the Netherlands has shown the total weight of plastic used in a 40m long by 12m wide stack using standard film to be 241.5kg whereas with an HOB sheet like Silostop Orange it was only 43.4kg – just 18% of the standard sheet weight.
This means that even with some allowance for variance in the alternative sheets High Oxygen Barrier sheets like Silostop Orange achieve excellent results with significantly less than half the volume of plastic and therefore half the plastic waste.
There are also savings in the energy required to produce HOB sheets with greenhouse emissions from the production process of conventional sheets being five times higher. (standard film 18.9Gj / HOB film 3.39Gj )
Sustainability does not stop at plastic waste as silage waste in stack itself is potentially more damaging from an emissions perspective. The growing and harvesting of a silage crop requires significant carbon inputs (fuel and fertiliser being key).
These are sunk costs, which are incurred before the silage is fed to cattle so the biggest influence, we can have on them is to ensure that the silage quality is as good as possible and waste silage as low as possible.
