Establishment, annual yield and nitrogen response of eight perennial grasses in a high country environment

Abstract

An experiment was established within the Lees Valley (400 m a.s.l.), Canterbury out of low producing, browntop dominant grassland. The aim was to quantify dry matter (DM) production of improved perennial grasses in relation to temperature and nitrogen inputs. Ten grass monocultures were established in 2006. For the first year, annual DM yield ranged from 4.2 t/ha (timothy) to 10.6 t/ha (‘Aries’ perennial ryegrass). On 15/8/2007 either 0 or 150 kg N/ha was applied to half of each plot. At the end of the spring 2007, yields were 1.3 t/ha (‘Aries’ no N fertiliser) to 5.5 t/ha (‘Revolution’ perennial ryegrass with N fertiliser). Yield responses ranged from 8.3 to 20.1 kg DM/kg N applied with an average spring growth rate of 3.2 kg DM/ha/°Cd for grass with no N and 8.8 kg DM/ha/°Cd for the N fertilised grasses, using a base temperature of 3°C. Results highlighted the need to maximise spring growth in summer dry environments, especially when there is a large potential response to the addition of N. Cocksfoot and tall fescue produced more DM in summer dry conditions indicating some opportunity to spread production through the year, in regions with highly variable summer rainfall.