THE PERFORMANCE AND SURVIVAL OF CONTRASTING NATURAL POPULATIONS OF WHITE CLOVER WHEN PLANTED INTO AN UPLAND FESTUCA/AGROSTIS SWARD

Abstract

A technique is described for the assessment of white clover populations implanted as rooted cuttings into an upland Festuca/Agrostis sward.Five natural populations of white clover, taken from widely different soils and habitat conditions, were tested by this technique on an acid soil, low in calcium and phosphate and just outside the natural limits of clover distribution.Throughout the experiment, populations from acid upland soils showed a superior performance and a lower percentage mortality than did populations from lowland calcareous soils and from medium‐fertility soil at a very high altitude.After two years, plants of the acidic populations alone remained alive, and of these only 19–25% of the number originally planted.The order of performance in the natural sward was an almost complete reversal of the order of performance as spaced plants on a high‐fertility lowland soil.The results indicate that the differential response to soil fertility factors, previously shown to exist between natural populations of white clover by soil‐ and sand‐culture techniques and by field fertilizer trials of spaced plants, became even more marked when the plants were subject to competition from native species.The possibility of breeding white clover varieties adapted to acid upland conditions is discussed, particularly in relation to compatibility with native species.