Mitchell grass es (Astrebla spp.) are the dominant component of the allu vial cracking clay grasslands of the Barkly Tablelands region in the Northern Territory, Australia. Mitchell grasses are native palatable, productive and perennial grasses that contribute significantly to cattle diet quality and quantity in the region. Several years of below-average rainfall resulted in a noticeable reduction in Mitchell grass tussocks in 2022. The Barkly Region component of the Rain Ready Rangelands (RRR) project trialled the commercial-scale application of wet season spelling to promote Mitchell grass recovery. The pastoralist-led demonstration used four paddocks on a demonstration site 440km north east of Tennant Creek, Northern Territory. Three paddocks were used in a wet season spelling rotation, with one paddock continuously stocked as a control. Farmbot „¢ telemetry units were used to record daily rainfall data remotely. Using the Botanal field sampling methodology (Tothill et al. 1992) data were collected from each paddock before and after the 2023/24 wet season inside and outside of new 100m by 100m cattle ex closures in each trial paddock. Changes in vegetation throughout the trial period were strongly influenced by successive high rainfall years, biomass increased in all paddocks both inside and outside of the exclosures regardless of management strategy. However, despite the high rainfall and moderate to low pasture utilisation, there was a tendency for a greater increase in total perennial grass basal area inside exclosures than in grazed areas. There was some early evidence from vegetation monitoring that recovery was enhanced inside exclosures and reduced in the poor (C) condition areas where there were very few pre-existing perennial grass plants. There was also a higher pasture growth response at the better land condition site with the same rainfall and grazing impact. This provides evidence of the benefits of promoting land condition recovery. We aim to continue to monitor the impacts of wet season spelling on Mitchell grass health in these paddocks through time.
Get reliable rangeland science
Toggle Search