XI. Otago Downland and Taieri Plain (Invermay)

Abstract

Pasture growth rates are presented for two sites on the Invermay Agricultural Research Centre farm. Growth on typical Otago Downland country was measured for 19 years and on the Taieri Plain for 12 years. Yields were obtained from grazed pasture cut by a standardised method using movable cages. The mean yield and standard error of individual samples over all years of measurement are given for standard dates at 14-day intervals. Although the plain site produced more herbage than the hill site, both growth patterns were similar, with a spring peak followed by declining yields through the summer to a marked winter depression from late May to mid August. About 6% of the annual yield was produced during the winter months of June, July, and August; 38% in spring; 38% in summer; and 18% in autumn. The growth pattern of the Lolium perenne component reflected that of the entire sward, reaching a peak at the beginning of November; Trifolium repens did not reach peak production until December and contributed 50% of its annual growth during the summer. This overall pattern of pasture growth is considered to be capable of supporting all-grass farming systems at high stocking rates, provided that proper management and pasture conservation techniques are followed. General climatological data, rainfall, and temperature during the period of pasture measurements are given for each site.