Oxygen barrier plastic: How much does it save? – Jon Urness, Vita Plus

By Jon Urness, Vita Plus national forage specialist

In reality, a better question would be “How much does it save?”

Weighing the option to use oxygen barrier plastic under conventional plastic is a great example of that scenario.  Research has shown you can expect a 10-percent decrease in spoilage in the top 3 feet of a bunker or pile (just under the surface of the plastic covering) by adding a layer of oxygen barrier film under conventional plastic.

As an example, let’s use a bunker that is 48-feet wide and 500-feet long filled with corn silage.  You have 1,800 tons of feed in the top 3 feet of this bunker (48 feet x 500 feet x 3 feet x 50 pounds of corn silage per cubic foot means 3,600,000 pounds (1,800 tons) of silage).  A 10-percent reduction in spoilage means 180 tons of corn silage could be saved.  If we value corn silage at $35 per ton, using oxygen barrier plastic just saved $6,300.

OK, now let’s find the cost to save that much.  We’ll need a piece of oxygen barrier film that’s about 52-feet wide, to accommodate slope, and at least 500-feet long.  At a cost of 6.5 cents per square foot, we’re talking an investment of $1,690 for the added layer of oxygen barrier plastic.  It’s also going to require some extra labor to lay it down, but that’s fairly minimal because the crew is already on hand to lay the conventional plastic.  Let’s estimate that a crew of 10 takes an extra hour to put down the oxygen barrier plastic.  At $20 an hour, it’ll cost about $200 for the extra labor.  Time is especially precious during harvest, but compared to the benefit, that extra hour to cover the pile is practically nothing.

Back to our original question, “How much do you save using oxygen barrier plastic?”  Using our example above, if we save $6,300 worth of feed and it costs $1,690 for the plastic plus $200 in labor to cover, the net payback is $4,410, or about a 3-to-1 return on investment.  In addition, you can expect reduced labor costs to pitch spoiled feed, less yeast and mold (both which can reduce dry matter intake), and fewer abortions and other metabolic disorders.

When choosing an oxygen barrier plastic, make sure it has been tested for oxygen transmission rate.  Ask for the data and be sure the number is lower than 50.  The lower the number the better, but we have seen little difference in performance when oxygen transmission rate is below 50.  Also, make sure the material clings to the contours of the silage surface.  One of the benefits of oxygen barrier plastic is its ability to tightly adhere to the silage surface and not allow air to infiltrate between the plastic and the feed.

Note:  Oxygen transmission rate (OTR) is a precise measure, in cubic centimeters, of oxygen penetration through a square meter of plastic in 24 hours.