2.2. Site management
The field was last ploughed, limed and re-seeded in
1990. Since then, it has been fertilised with 300 kg N
haÿ1 yrÿ1 as inorganic fertiliser together with variable
amounts of P, K and S, both as inorganic fertiliser and
as organic manure. Three cuts of silage have been taken
annually in May, July and September. For the present
experimental period (1999), however, organic manure
was not applied, and the total N fertiliser usage was
lowered to 250 kg N haÿ1 yrÿ1 in an attempt to optimise
the N content of the grass at ensiling (Keady and
O'Kiely, 1995).