Serrated tussock control at "Amyville", Fullerton NSW

When the 664ha “Amyville” sheep property at Fullerton, NSW was bought by the Clowes family in 2000, and placed under the management of Martin Croker and his team, the undulating to steep land was in poor shape. Large paddocks had been heavily over-stocked, leaving substantial areas of bare ground in the predominantly native pastures. Erosion was continuing unabated in the gullies, and at least 20% of the ground was heavily infested with serrated tussock. In 2000, no-one predicted the extent and depth of the decade-long drought about to begin, and the havoc it would wreak on both the landscape, and the lives of those who farm it.

It took Martin’s vision, experience and hard working team, coupled with consistent input and guidance from the Clowes, to turn the weed problem, land degradation and low stocking capacity of ‘Amyville” around, despite those ten drought years. Today, he sustainably runs 500 head of breeding cattle across the property, and has reduced the serrated tussock control to about 4 days spot-spraying/year.

Taking a whole-of-farm approach, Martin tackled the serious weed issues as part of a total re-appraisal of the carrying capacity of the farm, integrating the ability of the land to produce good returns while simultaneously improving the natural resources upon which the farm depends – year-round and self-mulching ground cover, soil vitality, water quality, and biodiversity.

The dense infestations of serrated tussock were initially boom sprayed with Frenock, taking some weeks per year to accomplish, and all smaller patches were spot sprayed. Once the tussock began to die, Martin then provided serious weed competition by introducing competitive perennial pasture species and soil improvement strategies.

After the initial application of MO Super, single super has been aerially sprayed across the paddocks at a rate of 100kg/ha, for the last 8 years.
To ensure the perennial pastures of the arable paddocks are maintained after the initial aerial seeding, Martin has direct drilled a mix of Lucerne, Phalaris, and 4 Fescue species – 2 of these fescues are summer active, and 2 are winter active.

As the paddocks began to respond to these treatments, and the pastures improved despite the drought, Martin began to alter his grazing management practices, introducing an adaptive rotational grazing system that could respond readily to feed availability and the nutritional needs of the stock whilst ensuring paddocks are never over-grazed.

The paddocks have been subdivided to allow for regular stock rotations, the timing of each paddock move dictated by the state of the pasture being grazed – the maintenance of year-round ground cover is critical. Each new paddock is watered via troughs that are gravity-fed by water from a large dam. The erosion gullies are now stabilized with stock-exclusion fencing, appropriate re-vegetation plantings, and natural regeneration of the native grasses on many of the bare banks.
Along many of the new fence-lines in the paddock sub-divisions, Martin has planted strategic shelterbelts of local Eucalypts, Acacias and other native shrubs. These not only offer protection to stock and increase microclimatic conditions to favor pasture growth, but they also capture some of the weed seeds blown onto the farm on the NW summer winds.

The serrated tussock problem is nowadays simply a maintenance problem, with scattered tussocks appearing yearly, from the large seedbed in the soil, the wind-blown seed from surrounding properties, and seed carried downstream along the creeks and river. Good ground cover, appropriate grazing strategies and improving soil health have ensured the serrated tussock no longer takes over. Taskforce is now used most of the year to spray the tussock, but if an occasional tussock is discovered close to seeding time, then Martin uses Roundup for an instant kill, spraying carefully to avoid killing the desirable grasses growing around the Tussock.

Many of the steeper paddocks are under native pasture, with a predominance of Microleana stipoides (Weeping Grass), Austrodanthonia species (Wallaby grasses), Bothriochloa scabra (Red Grass) and Themeda australis (Kangaroo Grass), with various Austrostipa species (Corkscrew grasses) in the poorest soils. These paddocks also have a good tree cover, and are managed as a productive and valuable part of the overall grazing system.

Today, paddocks that were bare, overgrazed, compacted and eroding, are covered with lush perennial pastures with almost 100% ground cover and an ever-deepening mulch layer. Protective shelterbelts are growing strongly. The pastures are very diverse, with sown exotic species, scattered native species, various medics, other legumes, and both native and introduced forbs. Such diversity of species in the pastures provides high-quality year-round nutrition for both the livestock and the soil biota; prevents excessive weed seed germinations, and continues to build topsoil.

Martin’s commitment to integrating his weed management strategies with a whole-of-farm approach is ensuring he remains in control of present and future weed invasion issues in a sustainable and cost-efficient manner.