How long should you wait to cut silage after applying Nitrogen?

First cut silage requires 80 to 100 units of Nitrogen (N) per acre from slurry and fertiliser, Anthony O’Connor, Teagasc Adviser in the Galway/Clare Advisory Region advises.

Excess Nitrogen in grass will inhibit silage preservation, according to O’Connor. He has said that a growing silage crop uses up two units of N/acre per day in good growing conditions.

Therefore, he advises to ensure that 50 days are left between Nitrogen application and cutting date to ensure full Nitrogen take up by the grass.

Grass management

By now most stock are out at grass, grass growth has been slow on farms due to a cold April, so continue to spread fertiliser to build up grass on your farm.

If grass is getting too strong in the next few weeks it can be taken out as baled silage.

Grassland management over the next few weeks will have a huge bearing on sward productivity and quality for the remainder of the grazing season.

Your first grazing should be as tight as possible to remove any dead material from the sward, he advises. Graze paddocks down to 4cm before seed heads emerge, which O’Connor says will ensure a leafy green sward later in the season.

A bag of CAN/acre can be spread when grazed out, he said.

Rotational Grazing

To ensure efficient grass utilisation and future supply, O’Connor said to consider dividing up large fields into paddocks using temporary electric fences and installing extra water troughs.

Water troughs are better placed in the middle of electric fence as opposed to either end of fence, which he said gives an option of further splitting paddock with a reel if grass gets ahead.

Start off by splitting one field with reels to see how you get on and work from there, he said.

Reseeded Fields

The Teagasc advisor said it is critical that any new reseeded fields are sprayed with a post emergence spray to kill any seedling weeds.

Farmers will spend €250-€300 per acre reseeding a field and then won’t spray a post emergence spray for the sake of less than €20/acre.

Spray reseeds after grass is at 3 leaf stage or roughly 5-6 weeks and after the emergence of grass sward, he advises to carry out a light grazing of new sward with weanlings, sheep etc. – this will encourage grass seedlings to tiller out.

Delay cutting any silage in the reseeded ground for 12 months, he recommends and if clover is in the new sward, use Legumex DB or a suitable selective herbicide.