Rolling and compacting silage: 6 tips for a firm pit

If too much air stays in your silage, heating and mould get a chance and you lose feed value. Only well-compacted silage preserves well, and that starts with rolling.

Why do you need to compact silage well?

With poor compaction, more oxygen stays in the material. After opening, that oxygen also gets further in from the silage face. This leads to heating and mould, and indirectly to lower feed value and more feed losses.

Good compaction also helps fermentation. Lactic acid bacteria only get to work once the last oxygen has gone. The whole chain from mowing to feeding is in the guide making and preserving silage.

How do you roll a pit well? 6 tips

1. Don't ensile too dry. Dry material is hard to compact and springs back easily. Grass compacts best at 35 to 45% dry matter (Groeikracht, a Dutch silage advisory group). Harvest forage maize at 32 to 36% dry matter (WUR, Handboek Snijmaïs). Do you have loads that are quite dry or stemmy? Put those in first. Then the weight of the rest of the silage presses them down. What else you can do is in dry silage.
2. Have the crop chopped. This gives an even material with a finer structure. That is easier to roll.
3. Work in thin layers. Spread grass in layers of up to 20 cm (Groeikracht). For maize, keep to layers of 30 to 40 cm. Then you can roll each layer well.
4. Make sure there is enough weight on the pit. See below for how much.
5. Roll an even pit. Avoid wheel ruts and other unevenness. That way you get no weak spots that are less well compacted.
6. Seal the edges well. Along the walls the feed is always hard to compact. That is why the edges are often a weak spot. Make sure the plastic fits tightly and airtight there. How to do this: the guide covering a silage pit.

How much weight do you need on the pit?

Put a weight of at least half the hourly intake on the pit. If 30 tonnes of fresh material come in per hour, roll with at least 15 tonnes. Don't use dual wheels: they lower the pressure per square centimetre.

Where is a pit least well compacted?

Usually along the walls and in the top layer. That is where most air is, so that is where heating starts first. Roll those spots extra carefully and make sure the cover fits tightly there. "When you see it lying like that, you can also see that the silage is tightly covered, especially at the edges," says Bouwman from Den Andel.

What do you do after rolling?

Cover the pit straight away. The longer it stays open, the more air and heat get into the feed. In a field trial with bales by Groeikracht, more than 6% of the dry matter was already lost after 2.5 hours of waiting (Veeteelt, May 2021). After that, keep rainwater out of the pit too, because water along the wall makes the edges extra vulnerable.

When feeding out, you notice whether you compacted well: air doesn't get as far into firm silage. See how Silage Safe covers the pit tightly after rolling on our product information page.