Liveweight production, dry matter yield and seasonal composition from dryland lucerne and lucerne/grass mixes over five years

Abstract

Liveweight production, dry matter yield and botanical composition of three lucerne based pastures (lucerne monoculture, lucerne/brome, lucerne/cocksfoot) were quantified for five years from a grazed, dryland experiment at Ashley Dene, Canterbury. The objective was to determine if liveweight production by sheep was enhanced by inclusion of a companion grass species with lucerne. Over five growth seasons (2012/2013–2016/2017) annual liveweight production ranged from 439 kg/ha (lucerne/grass mixes in 2016/2017) to 883 kg/ha (lucerne in 2013/2014). Liveweight produced from the monoculture was greater than, or equal to, that of the mixes every year. Dry matter yields ranged from 6.3 (lucerne and lucerne/cocksfoot in 2016/2017) to 16.2 t/ha/yr (lucerne in 2013/2014) primarily due to differences in in-season rainfall. Annual yield from the monoculture was less than, or equal to, lucerne/grass mixes in most years. The relationship between liveweight production and lucerne yield was strong (R² = 0.84). Earlier grazing of the mixes occurred in two of five years. After two years liveweight production from the lucerne/grass mixes was consistently lower than that achieved from the monoculture. However, in commercial situations drilling a runout lucerne stand with grass to extend stand life may be beneficial to provide an introductory feed prior to grazing a lucerne monoculture.