Introducing Perennials into Grasslands in South West Australia Increases Gross Margins for Dual Purpose Merino Enterprises

Dual purpose Merino enterprises on the south coast of Western Australia (WA) typically utilise agricultural grasslands that comprise entirely of annual plant species. These grasslands face a range of challenges including a variable Mediterranean climate coupled with mostly infertile fragile sandy soils. As a consequence livestock producers have to manage potentially high supple-mentary feeding costs particularly in summer and autumn while running sufficient livestock to remain profitable. Sowing summer-active perennial species into these grasslands has been shown through short-term livestock trials to allow an increase in stocking rates and reduce the amount of supplement fed. The objective of this investigation was to use a validated GrassGro simulation to determine the highest gross margin (GM) system for a dual purpose Merino enterprise over a 41-year period in contrasting rainfall environments by varying a range of management factors. The hypothesis tested was that the addition of summer-active perennials would consistently raise GM in all rainfall environments simulated