XII. Winchmore, Canterbury Plains dryland and irrigated pastures

Abstract

Pasture growth rates are presented for dryland and irrigated pastures at the Winchmore Irrigation Research Station, Canterbury. Yields were obtained from grazed pasture cut by a standardised method using movable cages. The mean yield and standard error of individual samples over 13 years of measurement are given for standard dates at 14-day intervals. Growth rates on both dryland and irrigated pastures were low during winter (June–August), and contributed about 5–8% of the annual yield. Forty–seven percent of the annual dryland production was in spring, with a peak in October, corresponding to peak growth of the dominant legume Trifolium subterraneum. Summer production was highly variable, and contributed only 24% of the average annual yield of 5870 kg DM/ha. Growth on the irrigated pasture was distributed more evenly throughout the year, with 35% of the annual yield in spring and 42% in summer. Growth rates were highest in summer, corresponding to the maximum growth of T. repens, and were much less variable than the dryland pasture. Annual production was 10 160 kg DM/ha, 73% more than the dryland pasture. General climatological data, rainfall, and temperature during the pasture measurement periods are given.