| Abstract: | Experiments were conducted on ryegrass swards using different amounts of N fertilizer applied as a single early dressing (S) or in repeated applications during the season (R). Over three years, the yield from R was generally higher, but under dry conditions (using plot covers) S gave the greater yield. The latter result is ascribed to the bigb yield obtained from S at the first cut, at which time N uptake was not limited by a lack of soil water. Irrigation at less than the full requirement resulted in lower total yields but it increased water-use efficiency by up to 70% (R) and 94% (S). |
