Improving maize silage quality: 8 tips for a better pit

How well your maize comes through the year depends on many things: the weather, your soil and how you ensile. You can do nothing about the weather. You can do something about harvesting and ensiling. With these 8 tips you get more quality out of your maize silage.

Why does the maize harvest vary so much by soil type?

In a dry year you see big differences between fields. Sandy soil holds moisture poorly, while clay and peat soils hold it well. Maize on sand therefore suffers more from drought. In a long dry spell, the roots on sandy soil can even die off. The crop then recovers more slowly when it rains again, and you see that in the yield. When it is best to irrigate maize is explained in when to irrigate maize.

Once the crop comes off the field, you can keep it good in the pit or let it go downhill. That is what the tips below are about.

At what dry matter do you harvest maize?

Harvest forage maize at 32 to 36% dry matter. Above 32%, there are no more effluent losses. Above 36%, the risk of heating and mould during feeding out increases (WUR, Handboek Snijmaïs). If heating is a common problem on your farm, aim for the lower end of that range.

How do you improve the quality of your maize? 8 tips

1. Start with a clean base

Clean the concrete floor and the access route before you start. That way no sand or soil gets into your silage.

2. Chop at the right length

Chop at 6 to 8 mm: according to the WUR maize handbook (Handboek Snijmaïs) that is the best length. Short-chopped maize compacts better and faster than a long-chopped crop.

3. Roll the maize pit well

Take your time and have enough machinery on the pit. Then little oxygen stays in the pit. After opening, less air gets in and less CO2 escapes. More on this in the 6 tips for good compaction.

4. Don't drive too fast

With a layer of 30 to 40 cm, 3 to 4 km/h is a good rolling speed. The rolling weight on the pit should be at least half of the amount of maize that comes in per hour. If 30 tonnes come in per hour, roll with at least 15 tonnes.

5. Ensiling over two days? Only roll once there is a new layer

On the second day, only start rolling once a new layer of maize is on the pit. If you drive straight over the old layer, you press out the CO2 that has built up there and fresh air gets into the silage.

6. Seal straight away and airtight

Airtight covering is one of the most important steps for the quality of your maize silage. Roll the pit evenly and finish the top smooth and slightly rounded, so no water stays on it (WUR). With Silage Safe you give the silage a rounded top, so the water runs away through the drainage. Jennissen in Den Dungen covers their maize pit with Silage Safe: "We're saving a lot of time and no longer have problems with heating." By keeping the surface nicely rounded and the cover tight, there's very little risk of heating. See how the system does this on our product information page. The full approach is in covering maize silage.

7. Use underlay film and new top plastic

Underlay film also helps to get the pit airtight. Use new top plastic instead of last year's: it can have small holes in it.

8. Keep to the right feed-out rate

Feed out at least 2 metres a week in summer and at least 1.5 metres in winter. So when ensiling, estimate carefully how high your pit should be. More explanation is in the right feed-out rate.

Where does maize often go wrong after opening?

After opening, maize is prone to heating: it contains a lot of sugars and starch that yeasts live on. Air that gets in at the edges, at the top or at the silage face gives them that chance. Good rolling, airtight sealing and a high enough feed-out rate are together your best defence. If you also want to improve your grass silage, see improving silage quality.