OBSERVATIONS ON THE DISTRIBUTION OF WHITE CLOYER STOLONS IN HILL SWARDS

Abstract

Hill swards under mob stocking by sheep at Taupo, Ballantrae and Wairarapa were sampled every three months for one year and white clover stolon dissected into three vertical classes: aerial, surface and buried. In 198081 swards at Ballantrae under three different grazing managements, rotationally grazed by cattle IRGC) and by sheep (RGS) and set stocked by sheep (SSS), were sampled six times over one year and white clover stolon dissected out. The distribution of stolon among the three vertical classes varied with season. Buried stolon ranged from a minimum of 42% in autumn to a maximum of 86% in early spring. The proportion of stolon in the aerial and surface classes peaked in summer at 14% and 48% respectively and was at a minimum in early spring (l%and 13%). Distribution of stolon among the vertical classes differed among sites. The Taupo site had respectively 12% and 17% less stolen buried than the Ballantrae and Wairarapa sites. Environmental conditions such as overgrazing during drought reduced the amount of white clover stolon by up to 70% and modified distribution in favour of the buried class. Grazing management had a large effect both on the amount of stolon in the swerds and on the morphology of stolons. Under RGC there was greater total stolon weight (570 kg/ha) than under RGS (310 kg/ha) and SSS (225 kg/ha). Stolons under RGC were heavier per unit length by 32% and 53% respectively than the stolons under RGS and SSS managements. Keywords: white clover, hill swards,stolons,grazing management, vertical distribution, stolon morphology.