8 March 2002

Reassess nitrogen growers advised

WITH wet weather set to continue, producers should reassess nitrogen and sulphur applications to avoid low protein in grass silage, as observed in the past two seasons.

Despite this spring being reported as the earliest for 300 years, it is actually late in production terms as wet conditions delay grazing and field operations, says Kemira north-west technical manager Mike Denny.

Fertiliser has only been applied on light free draining soils and many producers are eagerly waiting to apply the first dressing to silage ground, which is not likely until mid-march. But Mr Denny believes they should consider putting all of this on in one application.

"This ensures plenty of time for nitrogen to be used by the plant before cutting. At least nine weeks growth is required between fertiliser application and cutting for a 10t crop receiving 120 units/acre of nitrogen."

In previous years, delaying fertiliser applications has caught many producers out, forcing them to cut back on second dressings to avoid high nitrate levels in the clamp. This depresses yields and protein contents, which explains why some first cut silage only had a protein content of 10-12% this winter. &#42

Sulphur deficiency is another reason for low protein silage. Many producers in the midlands and coastal areas of Cumbria routinely apply sulphur dressings to boost sugar and protein in grass, adds Mr Denny. &#42