Harvesting each cut as cleanly as possible from the field, followed by optimal regrowth. The essence of cutting is determining the cutting height. The following applies: cutting slightly higher than needed ensures a cleaner cut of grass and encourages quick regrowth.
As a rule, cutting the grass to around 5 centimetres above soil level is advised. “But applying that cutting height as standard is not always the best strategy,” says Sjon de Leeuw, Advisor Management and Strategy at the renowned Dutch consultancy PPP Agro Advies1. “Several factors influence how you determine the correct cutting height: the age of the grassland plays a role; and another determining factor is the moment of harvest. It’s important all year round to avoid cutting the growing point of the grass as this seriously affects the chances of good, rapid regrowth.”
Cutting height and harvesting moment
In spring the growing point of the grass is slightly closer to the soil level than the level in mid-summer. It then becomes closer to the soil again in autumn. “That explains why you can’t cut your grass at the same height all year round,” says de Leeuw. “The growing point changes during the season and if you are harvesting from grassland that is a little older, then the cutting level may need to be higher – whatever the situation, it is important to adapt your cutting height during the season.” When harvesting grass for silage, don’t just concentrate on the grass you are cutting now, but think about the next cut. “Cutting higher may reduce the yield slightly, but you will quickly recover that loss within a week thanks to good regrowth. And that gives you benefits in the second cut,” explains de Leeuw. “Assuming you can harvest five cuts in a season, and they are cut at the right height each time, good regrowth means you can realise about two weeks of extra growth days.”
Minimal amount of crude ash in the grass
Once the correct cutting height has been determined, make sure all machines are correctly adjusted accordingly. “You can set the cutting height to 7 centimetres, but if the tedder, rake and pick-up of the silage chopper or loader wagon are not adjusted to that height, there is still a risk of crude ash in the grass. Adjust the machines accurately and always do a final check in the field. Drive a short distance, then get out and check the adjustment heights. Too high settings are not necessary but do make sure all the separate pieces of equipment are correctly aligned mutually for the best results.”