Publication Date

1997

Description

The responses of hexaploid Caucasian clover (Trifolium ambiguum) to four contrasting grazing regimes were compared with white clover (T. repens ) in a high endophyte hybrid ryegrass pasture on a fertile lowland site. After two years, frequent grazing reduced Caucasian clover cover to 10% compared with 25.5% in infrequently grazed treatments (mean spelling time 25 days). Similarly, Caucasian clover rhizome plus root dry weight was reduced by frequent grazing (78 g DM/m2 sampled to 100 mm depth compared with 322 g DM/m2). White clover was encouraged by frequent defoliation (21% cover) in contrast to Caucasian clover. Ryegrass tiller number was reduced from 5720/m2 in the infrequently and leniently grazed treatments to 4150/m2 in the frequently severely grazed treatment. These results show that in lowland ryegrass pastures on high fertility sites, the stoloniferous growth form of white clover may be superior to the rhizomatous strategy of Caucasian clover when grazing by sheep is frequent throughout spring, summer and autumn.

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Frequent Grazing by Sheep Reduced Caucasian Clover Cover and Rhizome Mass in Ryegrass Pasture

The responses of hexaploid Caucasian clover (Trifolium ambiguum) to four contrasting grazing regimes were compared with white clover (T. repens ) in a high endophyte hybrid ryegrass pasture on a fertile lowland site. After two years, frequent grazing reduced Caucasian clover cover to 10% compared with 25.5% in infrequently grazed treatments (mean spelling time 25 days). Similarly, Caucasian clover rhizome plus root dry weight was reduced by frequent grazing (78 g DM/m2 sampled to 100 mm depth compared with 322 g DM/m2). White clover was encouraged by frequent defoliation (21% cover) in contrast to Caucasian clover. Ryegrass tiller number was reduced from 5720/m2 in the infrequently and leniently grazed treatments to 4150/m2 in the frequently severely grazed treatment. These results show that in lowland ryegrass pastures on high fertility sites, the stoloniferous growth form of white clover may be superior to the rhizomatous strategy of Caucasian clover when grazing by sheep is frequent throughout spring, summer and autumn.