Grass experts at Barenbrug are urging growers to “go softly” with their first cuts, after the wettest 18 months ever recorded in England.
Barenbrug’s agricultural manager, Janet Montgomery, said that while grass is “amazingly resilient”, it is not invincible.
Montgomery said the issue lies in the soil beneath the grass more so than the grass itself.
“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,” she said.
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.
“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,” Montgomery said.
“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.”
Barenbrug said 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, it said.
Assess conditions
Montgomery said that, however tempting it may seem, growers should hold off until they have made a “thorough assessment” of their field and soil conditions.
“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,” she said.
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,” Montgomery said.
“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.”
Optimising machinery
Barenbrug advises growers to pay particular attention to power to weight ratios, tyre pressures and axle weights, as well as trailer sizes.
Once a field is deemed safe to travel, Montgomery said 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. 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, Barenbrug said.
“Set up the mower to be as flat as possible and again, don’t cut too short,” Montgomery said.
“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.
“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.”
