Go Softly for the First Silage Cut

“Go softly and the grass will thank you,” says Janet Montgomery, Barenbrug’s agricultural product manager.

“You don’t need me to tell you it’s been a wet winter. And while grass is amazingly resilient – certainly compared to winter crops that have suffered from waterlogging and flooding – it’s not invincible.”

In fact, it’s not so much the grass itself as the soil beneath it, Janet stresses. “With all that rainfall – 1,695.9mm, to be precise – soils have been thoroughly saturated again and again and again. They’re in a fragile state.”

In emerging or establishing crops, there is little protection for the top layer of soil, which can lead to soil erosion, a compacted top layer and the loss of aeration, Janet points out. “But established silage grounds will have a more mature, more robust root structure. That will have helped to maintain a more favourable soil structure, despite the saturation.

“However, with soils still so wet, it will be very easy to cause lasting damage even in those fields. And that will have a lot of knock-on effects down the line, especially with future silage yields,” she warns.

The added complication is the relatively mild winter which, coupled with an abundance of moisture, has seen grass reach an unusually advanced growth stage by this time of year. That will put farmers under added pressure to proceed with an early first cut.

Field by field

“However tempting it may seem, my advice would be to hold off until you’ve made a thorough assessment of the field and soil conditions,” she advises. “All that heavy silage machinery will play havoc with soil structure if it’s too wet – visible surface damage to the crop, and the deeper, unseen but often more damaging effects brought about by compaction.”

Soil types often vary across a farm, especially where ground is rented away from the main holding. “Obviously, if you can attend to lighter soil types first, there’s less risk of damage and you give more time for the heavier types to come good.”

Do what needs to be done to check fields, Janet says. “Look at the drains, see how wet the soil is, even dig a hole if necessary to see how saturated the soil might still be.”

Optimise machinery

Pay particular attention to power to weight ratios, tyre pressures and axle weights, as well as trailer sizes if you have a choice.

Once a field is deemed ‘safe’ to travel, Janet says cut height should be chosen very carefully. “Having taken every precaution to protect the soil, the last thing you want to do is to damage the sward!

“That can often happen when a heavy crop is cut very short,” she explains. “Just avoid the temptation to go for a bumper first cut. That’s why we say go softly. If you’re easy on it now, it will reward you later in the season.”

Avoiding contamination provides another good reason not to cut too close to the soil surface. Any damage caused earlier in the season – poaching, or wheelings, for example – can increase the risk of silage contamination from soil.

“Set up the mower to be as flat as possible and again, don’t cut too short. Not only will regrowth be quicker and better from having left a decent residue, but it also reduces any chance of the rake catching the soil as well as providing better traction in the field for raking and carting.”

Janet says a combination of factors could see a wide variation in silage quality this season. “When you’ve taken your first cut, if you’re not happy with the quality, then come and discuss it with one of the Barenbrug team at one of the events we’ll be attending this spring and summer, such as Grass and Muck, or Groundswell.

“Bring along some photos of the field too, and we can not only help you index it but also give some pointers for improvement or remediation.”