Hexaploid Trifolium ambiguum M. Bieb. (Caucasian clover cv. Prairie) persisted and dominated in high country plots which received more than 100 kg P/ha at establishment. After 13 years the biomass of coarse roots (rhizomes and tap-roots) amounted to 20 t/ha. The contents of nutrients in the root fractions were approximately five times that in the herbage. This ability to retain nutrients in coarse roots may be a strategy that contributes to the dominance of Caucasian clover on this acid soil.

Paper presented at the 56th New Zealand Grassland Association Conference, 17-20 October 1994, Hanmer Springs.