Evaluation of the use of a small leaved clover as an alternative to fertiliser-N on tetraploid and diploid perennial ryegrass swards grazed to controlled sward heights by ewes and lambs

Abstract

Lamb performance at grass falls in July/August on upland farms. Allowing sward height to rise has been recognised as having an ameliorating effect [Keeling, 1987). The objective of this trial was to determine the influence of both sward quantity (sward height) and sward quality [sward type) on ewe and lamb performance from mid April to September. A further objective was the evaluation of clover as an alternative to nitrogen fertiliser.Three contrasting perennial ryegrass based swards were established in May 1987 for use in 1988 and 1989: a late heading diploid variety (D). CONTENDER and a late heading tetraploid variety [T) CONDESA sown alone or with S184 small leaved white clover [TO]. [D] swards represent the control being the normal upland pasture type. [T] companion ryegrass varieties have higher palatability and intake characteristics and, producing fewer tillers, are a compatible companion grass to white clover. Small leaved white clover was used owing to its higher persistency and dry matter production under continuous sheep grazing.