Agronomy Advice
May 09, 2024

Cut for Quality

By: Philip Cosgrave

Thanks to an extremely wet few months, things are a bit later than normal this year. This may tempt some farmers to cut silage later than usual to keep the time intervals the same and hopefully grow more grass. But we would recommend keeping to your usual schedule, yes you may sacrifice a little yield, but you will maintain a level of quality in your silage which should keep your cows productive.

Dairy cow in a field
Dairy cow in a field

Quality over quantity 

Did you know that seed head emergence is determined by the initiation date which is influenced by day length, not weather? A one week delay in harvest date reduces silage D-value by 3.3% and protein by 2%. A 1% increase in D-value increases dry matter intakes by 0.22 kg/day and increases milk yield by 0.33 kg/day and can result in a concentrate feed saving of 0.44 kg/day.

Make your cutting decision based on the quality you require, rather than the quantity. This may be a bitter pill to swallow, but at this time of year, quality wins out.

Fertilise for yield

After securing quality with that first cut, you can then fertilise for that second cut that will hopefully start to make up for lower first cut yields.

Our recommendation is to spread 90-100 kg/ha nitrogen, 25 kg/ha phosphate and 90 kg/ha potash. YaraMila Silage Booster will deliver just what you need as it’s a formula Yara have developed specifically for grassland farmers growing for silage. Spread 450 kg/ha immediately after your first cut to maximise second cut yields and offset any losses from earlier in the season.

If you have slurry to spread, you may only have a requirement for nitrogen and sulphur depending on the volumes of slurry available. If you’ve enough phosphate and potassium from your slurry, then 330 kg/ha of YaraBela Axan is needed.

Don't forget about sulphur 

If you’re adding nitrogen, you should include sulphur; they work hand-in-hand as building blocks for protein, so the two nutrients should be applied at the same time. Just as with nitrogen, sulphur leaches easily so you should apply it little and often throughout the growing season.

Applying fertilisers containing both nutrients means that the grass will use nitrogen more effectively resulting in more kilograms of dry matter per kilogram of nitrogen spread. An improved nitrogen use efficiency is something we all aim to achieve - gives you more bang for your buck and protects our environment... it's a win-win!