Productivity and water use of five pasture grasses in Canterbury

An experiment was conducted on a fertile Wakanui silt loam in 1991/1992 examining yield and water use of five perennial pasture grass species, Grasslands Hakari mountain brome (Bromus sirchensis), Grasslands Wana cocksfoot (Dactylis glomerata), Grasslands Roa tall fescue (Festuca arundinacea), Grasslands Marsden perennial ryegrass (Lolium perenne x Lolium hybridum), Grasslands Maru phalaris (Phalaris aquatica). From 8 November 1991 until 31 March 1992 the highest yields were from Hakari and Maru at 11370 and 10870 kg/ha. Marsden, Wana and Roa yielded 8960,875O and 8190 kg/ha respectively. From late January until the end of March growth conditions were not limited by water stress or nutrients. Pre-irrigation yields, when rainfall limited growth were 3840,3570, 2720, 2520 and 2290 kg/ha for Hakari, Maru, Marsden, Wana and Roa respectively. Total water use was not significantly different between species and averaged 400 mm. Water use efficiency (WUE) was significantly higher for Hakari and Maru at 30.1 and 27.9 kg DM/ha/mm respectively. The other three species had WUE’s less than 23 kg DM/ ha/mm of water. Neutron probe measurements showed all species extracted soil water from a depth of at least 110 cm