Covering silage in a storm: the plastic has blown loose, now what?

After a long day of harvesting, covering the pit is already hard work. In strong wind it becomes a nasty job, especially at the maize harvest in autumn. Even in a fresh breeze it is hard to keep the plastic in place without it blowing up again. And once it lies tight, it has to stay that way all winter.

Why does the plastic blow off your silage?

Once the wind gets under a loose edge, it takes hold of the plastic. That happens mainly:

• while covering, when the plastic isn't held down yet;
• at the edges, where tyres and soil don't stay in place well;
• after a few weeks, when the silage has settled and the plastic lies looser;
• when you add another cut, because the pit is opened and closed more often and is often covered less well in between.

Tyres only give weight in one spot. In between, the plastic can still move.

Can you cover silage when it is very windy?

Yes, if you work quickly and in a controlled way, with one person in charge. Have everything ready beforehand: underlay film, silage plastic, covers or a covering system and a few long sandbags.

1. Lay the plastic over the walls before you fill the pit. Pull it down to the floor and leave a good length lying on the floor. With Silage Safe you leave at least 20 centimetres on the floor. Then the plastic is already held at the wall on one side. How to lay it out is explained in silage plastic, underlay film and side-wall plastic.
2. Pull the underlay film over the silage first. Put a few long sandbags on the edge on the windward side, or let people hold the plastic down on the ground.
3. Pull the flap on the windward side over the silage, into the wind. Work fast and keep the plastic as low as possible.
4. Then pull the flap from the other side over the silage, with the wind. Now the wind can't get under it any more.
5. Hold the plastic down straight away. Quickly throw some weight on it, or secure a first row of covers of your covering system. Make sure the edges are well sealed too.

Working with Silage Safe? In strong wind, first secure one cover at the front, one in the middle and one at the back. Then lay the rest, starting at the back. As soon as a cover is secured, the plastic underneath is held too. Geert Mulder from Balkbrug (NL): "Wind is much less of a hassle now. As soon as we secure a row of covers, the plastic stays put." See the system on the product information page.

The full step-by-step plan, from preparation to feeding out, is in covering a silage pit: step by step.

The plastic has blown loose: what do you do now?

The longer the plastic lies loose, the more air reaches the silage. When oxygen gets into the silage, yeasts become active again and the silage starts heating. So act quickly.

1. Put the plastic back and hold it down straight away, starting on the windward side. Work low, so the wind doesn't get under it again.
2. Check whether the plastic is torn. Holes and tears let in air and rainwater. Repair them before you cover the silage again.
3. Check for air pockets under the plastic. Pull the plastic and the cover tight again.
4. Check the edges. That is where most air gets in, and where water runs in too.
5. Keep an eye on the spot when feeding out. Where air or water has reached the silage, heating or mould can develop. Remove bad patches, so they don't spread further.

If rainwater has run into the silage, see rainwater in silage.

How do you stop the plastic blowing loose again?

• Make sure there is pressure across the whole pit, including the edges. Then the wind gets no grip on the plastic anywhere.
• Pull everything tight again after a few weeks. In the first weeks after ensiling, the silage settles a little more and the plastic becomes looser.
• Every time you add another cut, cover it just as well as the first time.
• Keep pests away. Loose plastic and gaps attract birds and other pests, and they make new holes.

Do water tubes or sandbags on the silage help?

Water tubes, sandbags and long sandbags give weight where they lie, just like tyres. While covering, they help keep the plastic in place on the windward side. But they only give pressure in one spot. In between, the plastic can still move, and like tyres they don't stay in place well on the edges. For silage that has to stay tight all winter, you need pressure across the whole pit, including along the walls.