WHITE CLOVER GROWTH AND MORPHOLOGY IN DAIRY PASTURE IN THE WAIKATO REGION OF NORTHERN NEW-ZEALAND

Seasonal changes in clover plant growth and structure in a Waikato dairy pasture were monitored over 1 year. Pasture plugs and clover plants separated from turves were removed from paddocks before grazing. They provided data on clover plant density, total stolon biomass, vertical distribution of stolons in the sward, and various morphological characteristics. Plant density averaged 610 plants/m2 which was higher than that recorded in a comparable study of Manawatu sheep-grazed pastures. Stolon biomass was also greater in the dairy pasture; most of this stolon was on the soil surface (58%) whereas in sheep-grazed pastures most was buried. The proportion of stolon within each class varied throughout the year. Clover plants fragmented during spring as was shown for Manawatu sheep pastures. Plant density therefore peaked during spring while values for plant morphological characteristics were low since most of the clover population comprised small, 1st-order plants. Overall, clover plants in Waikato dairy pastures were larger than those in Manawatu sheep-grazed swards. These differences probably resulted from interactions between several factors including cultivar, climate, soil type, companion species, farm management, and grazing effects.