Silage swards maturing rapidly – prepare for an early harvest

Gareth Smyth (right) inspects a sward of hybrid ryegrass with local CAFRE Dairying Adviser William McCulloch.  With a heavy crop and seed heads about to emerge, Gareth had decided to cut the crop on 2 May – over a week earlier than previous harvests.  His fields of mid-season perennials are also maturing rapidly and weather permitting should be cut within the next fortnight, again well in advance of normal harvest dates.

The exceptionally good growth conditions this spring mean similar plans for early harvest should be made by the majority of producers.  Concerns about high nitrogen levels in the grass due to late fertiliser and slurry applications should be unfounded as up to 3KG N/ha (2.5 units/acre) is used up in good growing conditions.  A good wilt (25-30%) will also reduce the impact of  high nitrogen levels – so don’t delay harvest if the weather stays good.

You should be walking crops over the next two weeks to assess seed-head development.  Grass cut as seed heads start to appear will produce a high quality silage 67-70 D (digestibility).  Where slurry was applied in March, take a look at the base of the sward to assess contamination with dried slurry.  If residue levels are high, consider raising the mower 2-3 cms to reduce the level of contamination in the silage.