REGENERATIVE AGRICULTURE CASE STUDY
BUILDING LANDSCAPE RESILIENCE YOU CAN BANK ON
ENTERPRISE: Dorper Sheep and Boer Goats, opportunistic feral goat harvesting
PROPERTY SIZE: 10,00 hectares
AVERAGE ANNUAL RAINFALL: 400 mm
ELEVATION: 260 m
PRACTICES COMMENCED: 2005
RESILIENCE BUILDING PRACTICES
- Implementing total grazing pressure fencing to control the access of unmanaged goats and kangaroos to pastures.
- Developing two grazing systems, one intensive, applying all available management techniques to improve landscape performance on developed areas of the property, and one extensive, using fewer resources and maintaining a degree of production on as yet undeveloped areas.
- Using a planned (holistic) rotational grazing system on intensively managed paddocks providing periods of rest for pasture to fully before re-grazing.
- Constructing water-spreading contour banks to slow and spread surface running water after rain.
- Selected mechanical and chemical removal of invasive native scrub to reinstate a grassy open woodland mosaic.
- Trapping feral goats and reinvesting income into further infrastructure developments to reduce goat impact on the landscape.
- Building a more resilient business and landscape by improving landscape ecological function.
- Continually increasing groundcover and diverse palatable perennial species in intensively managed paddocks regardless of seasonal conditions, delivering greater consistency of production and growth response to rainfall.
- Producing biomass of over 4000kg per hectare on initial intensively managed paddock in April 2014, up from 125kg per hectare in the same paddock in 2005.
- Ability to run four-times the Livestock Health and Pest Authority (LHPA) assessed stocking capacity on 20% of the property.
- Stopping erosion and improving rainfall infiltration, lifting previously bare paddocks to a new level of productivity within the intensive area.
- Developing a management system that allows advanced planning and improved ability to take advantage of stock sales and changes in seasonal conditions.
- Establishing a program of continual landscape and production improvement, reinvesting to expand high-performance managed areas of the property.
- Building a stable and reliable business that has reduced personal and family stress and markedly improved family lifestyle.
BUILDING RESILIENCE TO THE IMPACTS OF DROUGHT
A landscape that is most resilient to the impacts of drought is one with high proportions of continual groundcover, supporting healthy soils and effective rainfall infiltration and retention. Such a landscape supports a biodiverse ecosystem with healthy nutrient cycles of growth, breakdown and decay.
Many years of over-utilisation of natural resources in the Western Division have resulted in significant degradation of landscape condition, leading to sparse groundcover, widespread incursions of invasive native shrubs and trees, exposed hard-capped soils and a cycle of continuing degradation. Combined with the extremes of climate this region is subject to, the landscape and pastoral production are particularly susceptible to the impacts of drought.
Innovative farmers in the region however, are illustrating that this vulnerability is not a result of any fragility in the landscape, but conversely, that active management can restore landscape health, build a regenerative cycle and deliver sustainable production regardless of seasonal conditions.
Ashely and Carolyn McMurtrie, of Gilgunnia Station north of Cobar, have, over the last 10 years, commenced a program to build a successful enterprise and regenerate their 10,000 hectare landscape. They now run a successful Dorper flock ram and commercial lamb breeding business, and, having significantly improved 20% of their property, are well on their way to building all of Gilgunnia into a resilient state.
The key factors influencing the resilient landscape and business being built on Gilgunnia are:
- Implementing total grazing pressure fencing, enabling control of wild and domestic grazers and allowing pasture rest and recovery.
- A focus on increasing and maintaining groundcover, particularly palatable perennial species, which also protect the soil and increase rainfall infiltration and retention.
- Starting with development of one high-performing paddock to produce biomass that can be relied on when conditions require, then expanding across the property.
- Running the greatest value stock on the feed available to maximise profits within the carrying capacity.
AGRICULTURE ON THE COBAR PENEPLAIN
Gilgunnia Station is part of Australia’s extensive rangelands which cover 75% of the continent. Gilgunnia comprises 10,000 hectares on the Cobar Peneplain, on the eastern edge of the Western Division of NSW. The Cobar Peneplain is one of six bioregions that lie in Australia’s semi-arid climatic zone. Summers are characterised by hot, persistently dry weather interspersed with rare storms with often heavy rainfall. Since the current series of measurement began in 1962, Cobar has received an average annual rainfall of 398mm, ranging from 101mm in 1982 to 710mm in 2010.
There are no natural surface waters on Gilgunnia, and few elsewhere in the area. Stock and domestic water supplies are provided by ground tanks (dams) of up to 10m deep filled by surface run-off. Water supply from these tanks is generally reliable due to their depth and there is usually sufficient rainfall in summer to replenish them, despite high evaporation rates.
Gilgunnia consists mainly of rangeland in a natural state but of varying condition. Soils on the property are predominantly red earths, shallow on the gravelly rises but deeper on the drainage flats. Nutrient stores in soils, particularly in the rangelands, are generally held within the upper few centimetres of the soil, but on Gilgunnia, like many properties in the region, most of this material had been lost through sheet erosion. Soils become hard-capped through this declining surface structure which consequently reduces rainfall infiltration. Bare ground and a lack of perennial grass presence have contributed to hard-capping and low levels of soil carbon and subsequently the landscape is highly susceptible to the impacts of short term and multi-year droughts.
The soil landscapes of Gilgunnia support typical plant communities found across the Western Division. The natural vegetation on the gravelly rises is mulga (Acacia aneura) woodland with a shrub layer of turpentine (Eremophila sturtii), budda (Eremophila duttonii), punty bush (Cassia eremophila) and emu bush (Eremophila longifolia). These also host sparse groundcover of copper burr (Sclerolaena parallelicuspis) and occasionally speargrass (Heteropogon contortus). The broad drainage flats support sparse poplar box (Eucalyptus populnea) with a dense shrub cover of mainly turpentine with sparse groundcover and isolated perennial grasses.
Over a century and a half of continuous grazing in the region, combined with periods of carrying large stock numbers into multi-year droughts caused considerable and widespread land degradation and obvious changes in the condition of the native vegetation. A particularly damaging period occurred in the late 1800s and early 1900s which coincided with devastation caused by rabbit plagues. Likely as a result of these historical management practices, turpentine, budda, punty bush, emu bush and mulga now act as invasive native species (INS) in this landscape, forming dense thickets across broad areas.
Left unmanaged, this landscape is vulnerable to further degradation. Linear surface features such as tracks and grader windrows are a known cause of rill and gully erosion. Dispersed sheet runoff flows are concentrated by these features, causing extensive erosion systems that drain moisture from surrounding areas.
REGIONAL MANAGEMENT CHALLENGES
Conventional management in the district over many decades has typically consisted of continuous or set stocking of Merino, and more recently Dorper sheep and the opportunistic harvesting of feral goats (Capra hircus). An absence of predators and abundance of man-made water supplies has allowed populations of feral goats and kangaroos to proliferate. Many properties in the Western Division are not able to manage forage resources, particularly in times of drought due to the presence of these unmanaged grazers, which can comprise up to 50% of total grazing pressure on the landscape. 1C. Waters, G, Melville, A. McMurtrie, W. Smith, T. Atkinson, and Y. Alemseged (2012), The influence of grazing management and total grazing pressure fencing on groundcover and floristic diversity in the semi-arid rangelands
Goats are hardy under drought conditions due to their ability to browse trees and shrubs and utilise a wider range of forage than other stock. Moreover, these unmanaged grazers are not constrained by conventional pastoral fencing and actively migrate to where the feed is growing, regardless of paddock boundaries.
Both these nomadic grazing animals ensure that pastures in the region are constantly over-utilised and that groundcover is minimal. This leads to reduced infiltration of available runoff and the replacement of palatable and perennial pastures with unpalatable or annual species. Such high grazing pressure causes groundcover to be dominated by annuals, and pasture production occurs in short episodic growing seasons followed by induced ‘drought’ conditions. Under these conditions and with the onset of seasonal dry periods, animal production is dependent on the ability of stock to browse trees and shrubs.
Consequently, pastoralists are unable to conserve feed for drought and stock must continually compete with the unmanaged goats and kangaroos. The downward spiral of bare ground, degraded nutrient levels, poor infiltration of rainfall, limited recruitment and rehabilitation of adapted plant communities results in these landscapes being highly susceptible drought and to the impacts of post-drought heavy rains.
When Ashley and Carolyn McMurtrie arrived at Gilgunnia in 2004, the landscape and soils had experienced many decades of traditional pastoral management and were depleted and degraded. The conventional business model previously used on the property did not demonstrate the ability to manage natural resources for either production or natural resource goals.
REGENERATION FOR RESILIENCE
The McMurtries arrived in the region from the east coast and settled on Gilgunnia. The property was run-down without a single paddock that effectively held stock and in the early stages of what was later to become known as the Millennium drought 2A.I.J.M Van Dijk, H. E. Beck, R. S. Crosbie, R. A. M. de Jeu, Y. Y. Liu, G. M. Podger, B. Timbal, and N. R. Viney (2013), The Millennium Drought in southeast Australia (2001–2009): Natural and human causes and implications for water resources, ecosystems, economy, and society, Water Resources Research, Vol 49, Issue 2. It was evident that previous management models were not working. Ashley and Carolyn were consequently driven to seek new ideas on rangeland management in order to make a viable living.
Their research suggested that when originally settled, the Cobar Peneplain comprised grassy open woodlands, a legacy of Aboriginal burning practices. In the mid to late 1800s of settlement and pastoral development the Western Division vegetated landscape carried a much higher number of sheep than it does today. The gravelly rises would have supported open shrubby vegetation with a groundcover of annual and low perennial grasses such as bandicoot (Monachather paradoxa) and mulga Mitchell grasses (Thyridolepis mitchelliana). The drainage flats would have supported an open woodland of poplar box with a dense cover of robust perennial grasses including kangaroo (Themeda triandra), Queensland blue (Dichanthium sericeum), red-leg (Bothriochloa macra) and curly windmill grasses (Enteropogon acicularis).
In the face of the reality of Gilgunnia, Ashley and Carolyn decided to investigate what management practices they could apply to restore a productive landscape with such vegetation.
EDUCATION & TRAINING
The McMurtries sought local advice and easily identified who to approach as these people were running viable businesses despite the drought conditions. This included those who used traditional business models but maintained an extraordinary work ethic, as well as those who were actively applying new ideas to work with nature and natural cycles.
Through these local relationships they were introduced to Holistic Management, which has since been consolidated with formal training with Holistic Management educator Brian Marshall. Holistic decision making provides a framework for considering all resources and management tools in working towards a specified goal.
Planned rotational grazing (also referred to as holistic planned grazing) is a key Holistic Management practice. This practice aims to replicate the natural behaviours of large grazing animals on the landscape – where large herds graze an area intensively for a short period and then move on, not returning until pastures have fully recovered. These grazing methods encourage more abundant and diverse pastures and the opportunity for pastures to rest.
Management of total grazing pressure combined with planned rotational grazing provide the tools to restore landscape health and maintain production.
The McMurtries participated in a Resource Consulting Services (RCS) Grazing for Profit course in 2006 and a follow-up Pasture to Pocket course in 2009. The Grazing for Profit course involves holistic integrated management training which focuses on the use of natural plant, animal and water cycles as an integral part of on-farm decision making 3RCS Core Courses, Grazing for Profit www.rcsaustralia.com.au/products/family-business/grazing-for-profit-2/. Whilst informative, Ashley found that some of the teachings from this course were less applicable to the drier conditions of the Western Division and his breeding enterprise, than to the eastern environment for which they were developed.
Ashley and Carolyn also established a relationship with the Western Catchment Management Authority (CMA), now Local Land Services (LLS) Western Region, for advice, funding opportunities, and participation in programs and research, a relationship which they have maintained ever since.
They participated in the Western CMA Western Innovators Program, a farmer to farmer mentoring program which aimed to increase the capacity of landholders to manage their properties for the protection of soil, biodiversity and other ecosystem services, as both a participant in 2012 and later in 2013 as a mentor.
Ashley and Carolyn also developed skills in Geographic Information System (GIS) mapping and completed a year of an Environmental Science degree. However, the latter was discontinued as much of the material presented was found to be dated and not helpful for practical property management.
Ultimately the McMurtries identified that management of total grazing pressure, the combined grazing pressure exerted by all stock – domestic and wild, native and feral – on the vegetation, soil and water resources of the property landscape, combined where possible with planned rotational grazing, would provide the tools by which they could restore landscape health and ecological function and maintain production – regardless of seasonal conditions. And so they conceived the dual system grazing model.
Their relationship with local innovators Andrew and Megan Mosely of Etiwanda has provided an ongoing mentorship and helped the McMurtries to develop a holistic framework for making decisions on their property. The Moselys have vast experience in implementing total grazing pressure management and holistic grazing systems in the Western Division, and they initially assisted Ashley and Carolyn in developing a property management plan for their dual system grazing model.
The dual system grazing model applied on Gilgunnia includes a combination of intensively managed grazing across 1,000 hectares and extensively managed opportunistic grazing over the rest of the property.
The dual system was developed as a risk management approach. Implementing the intensive grazing system and with best practice techniques was capital intensive with – at the time – unknown outcomes, although others had used similar approaches with success. There were no case study examples of the range of best-practice approaches being used together. Risk was mitigated by developing the extensive system at the same time, as results were better understood with this model. The intensive system was also developed incrementally, trialling each new technique in a test paddock to see how the landscape responded, before application to other paddocks, as time and resources allowed.
The first stage of implementing the new grazing management system was the construction of goat trap facilities on all water sources to provide cash-flow to fund total grazing pressure (TGP) fencing and to begin reducing goat impact.
INTENSIVE GRAZING SYSTEM
Intensively managed grazing attempts to increase production or utilisation per unit area or production per animal through a relative increase in stocking rates, forage utilisation, labour, resources, or capital.
On Gilgunnia this has involved the construction of secure TGP fenced paddocks, with all wild grazers removed. There are currently seven paddocks of between around 48 and 156 hectares over a total of 1000 hectares in the intensive grazing system. The aim is for paddock sizes to eventually be between 120 and 160 hectares, which are considered small for the Cobar district. Smaller paddock sizes enable accurate pasture monitoring, are easier to keep free of unmanaged grazers and easier to maintain infrastructure.
The McMurtries have applied a range of best practice techniques in most of these paddocks, most trialled in one paddock first. As resources have allowed, in a number of paddocks Ashley has performed mechanical and chemical removal of INS to restore open woodland. Though acknowledged as not ideal due to risk of wind and water erosion of the exposed soil, Ashley has ploughed a number of paddocks to fully remove the pervasive turpentine bush. A side benefit of this practice however, is that it helps to break up the claypan and kick-start conditions for moisture infiltration and germination opportunities. Such a result is often achieved by large mobs of cattle in other holistically managed properties.
Water-spreading banks (explained in more detail below) have also been constructed on a number of paddocks. Depending on rainfall, it does not take long for colonising pioneer species to appear in these areas of improved water retention. After a period of rest to let plants establish, planned rotational grazing is implemented and timed according to a desired level of pasture utilisation and the trigger points of specific species that are being encouraged.
Other paddocks in the intensive grazing system have not been cleared, ploughed or had water-spreading banks constructed, but are still showing continuous improvements to ground cover and forage growth through the TGP control and recovery time allowed by planned rotational grazing alone.
The intensive grazing system requires more skill in management and attention to detail. For example, grazing strategies are based on regular monitoring of pasture species and the identification of trigger points. Close monitoring of unwanted grazing animals is also necessary to ensure that pasture objectives are met during the spelling phase.
EXTENSIVE GRAZING SYSTEM
Extensively managed grazing uses relatively large land areas per animal and a relatively low level of labour, resources, or capital.
The McMurtries practice this over the 9,000 hectares of their property not yet developed for intensive management. This area is usedfor opportunistic grazing when there is adequate forage, while maintaining the capacity to destock when conditions deteriorate.
Two paddocks within this system of 690 and 741 hectares are also enclosed with TGP fencing and provide more reliable feed availability than remaining paddocks during poorer seasons. This system is evolving as funds become available to erect further perimeter TGP fencing. In the interim, unmanaged goats are strategically harvested to reduce their impact on groundcover and forage resources.
Both grazing systems incorporate TGP management through the use of hingejoint fencing systems. This TGP fencing to control the goats and kangaroos generally consists of 7/90/30 hingejoint fencing supported by top, middle and bottom support wires, topped by plain or barbed wires.
The fencing is designed to provide a strong physical and psychological barrier to prevent unwanted grazers access to the paddock. Higher fencing that provides a complete physical barrier in all places at all times was assessed as too prohibitive a cost.
The hingejoint fencing used is seen as relatively easy to erect and maintain, and cost effective given the distances required and its long lifespan. Fencing designs on Gilgunnia have evolved with experience over time, with initial fences incorporating both hingejoint wire and electric offsets. However, based on personal choice, the typical fencing arrangement now comprises 7-line hingejoint with 9 metre post spacing.
Originally the ten ground tanks situated across the property and filled by surface water runoff and rainfall provided all stock water. These were open to stock and unmanaged grazing animals at all times, providing no checks on unwanted consumption or contamination. All ground tanks have now been fenced and stock water is supplied by a combination of concrete and plastic troughs and some direct access to the ground tanks, which is slowly being replaced by a trough system. Where possible water is supplied in corners of interfacing paddocks to lessen costs of infrastructure and to ease mustering.
The Livestock Health and Pest Authority (LHPA) provided an initial assessment, based on standard practice in the region, of a carrying capacity of 1400 DSE across the then entire property of 13,000 hectares. However, initially the property could only run goats due to the poor condition of pasture and the only forage available being by browsing trees and shrubs. Boer goats were introduced and used as a land management tool as they were able to browse certain shrubs aggressively and remove pasture weeds such as Paterson’s Curse (Echium plantagineum) and Bathurst Burr (Xanthium spinosum). With improving landscape condition after TGP fence erection, pastures became better suited to running sheep.
A Dorper flock ram and commercial lamb production enterprise was then developed, producing a much higher value animal than Boer or feral goats for similar grazing pressure. Dorpers are of robust build, provide good meat and are highly suitable for variable rangeland conditions. Their strong survival drive does mean they will push through less substantial fencing if feed is required. However, with TGP fencing and the regular quality feed provided by planned rotational grazing, they are a valuable product on Gilgunnia. Ashley currently runs a flock of 900 DSE over 2000 hectares – four times the LHPA assessed rate. These numbers are increasing as the intensively managed system expands and matures.
In the last 12 months a few cattle have also been introduced on to the property. Run in a single mob with the sheep, the impact of the cattle complements the management of the other stock within the intensive system, delivering the benefits of multi-species grazing.
To most effectively respond to changing seasonal conditions and feed availability, Ashley still maintains a herd of Boer goats, which are run in the same mob as the sheep and cattle. These Boer goats are maintained as a self-replacing flock of lower dollar and emotional value, which can easily be sold to reduce stock numbers and grazing pressure if conditions require. This enables Ashley to maintain his Dorper production flock regardless of conditions and ensures that landscape condition is always improving, as matching the stocking rate with carrying capacity is fundamental to this grazing management system.
FERAL GOAT MANAGEMENT
Opportunistic harvesting of feral goats comprises a significant income stream for many properties in the region and on Gilgunnia has been the principal stream for financing property improvement and furthering development of both grazing systems. The opportunistic harvesting of feral goats is highly dependent on local populations, seasonal water supply – goats are hard to trap when surface water is abundant – and a fluctuating price from processors in response to demand, supply and international prices.
Each of the ground tanks on Gilgunnia has now been fully enclosed by TGP fencing, with specific gates and pens constructed to form the trap yard. Access to the water is only possible through the specially designed trap gates. These gates work by allowing access through a set of spring-loaded spears, and exit through a second set. These are both left open so that the goats become accustomed to moving through the gates to access the water. The exit gates are then locked closed so that the goats cannot escape.
Ashley typically traps feral goats four to five times a year, mostly during the warmer seasons from October to April when there are no alternative sources of water. Trapping is generally performed across the whole property at the one time, which also enables Ashley to perform a form of census of the goat population. Trap yards are generally set across a three day period to trap not only the nannies and kids, but also the billy goats which can be more suspicious and hold out longer to access the water. The goats are then moved through a wing in the enclosure up to a set of yards where they are sorted and moved to a central set of yards to be transported for sale.
In unmanaged landscapes in the region groundcover levels can be less than 20% for much of the time, so heavy rainfall rapidly runs off the gravelly rises and through the flats without infiltrating. Runoff typically forms as sheet flows into broad drainage flats that traverse the property, flowing on to neighbouring land. Ground tanks fill rapidly during storm rain, reflecting poor infiltration across the landscape.
In order to help address this issue, the McMurtries have invested in landscape engineering in the form of water-spreading banks in a number of paddocks in their intensive system. This technique includes the construction of a series of earth contour banks and channels that repeatedly reduce the velocity of runoff and spread flows across broad areas. It also provides the landscape with the maximum benefit from isolated or smaller rainfall events. This improves infiltration, reduces the concentration of flows and promotes the growth of perennial pastures towards the ridge lines. The then Western CMA provided the layout service to deliver the specific design required for the banks to be effective.
Water-spreading is suited to broad flats between 100 metres and 1 kilometre wide. The system contains a series of banks on the contour, holding and spreading water through the system. The banks serve to stabilise erosion (gully or rill erosion) and increase water infiltration. Water-spreading systems increase soil nutrients and groundcover over time.
In this region of the Western Division, the full benefits of water-spreading can only be realised if it is part of a TGP control system with managed planned rotational grazing, in order for the land to be rested for new pastures to establish.
The environmental benefit of these water-spreading banks on Gilgunnia is obvious to an on-site observer. The banks are slowing runoff and improving infiltration on otherwise degraded soils. For example, a paddock completely cleared of INS 12 months previously is now covered with a diverse range of plants and increasing numbers of desirable perennial species, all from existing seed bank reserves in the soil.
The initial trial paddock, already recovering prior to the construction of water-spreading banks in 2012, appears dramatically different to the surrounding landscape with a dense cover of red-leg grass and increasing numbers of other palatable perennial species.
Recently, landscape engineering changes have also been made to reduce runoff diversion and erosion resulting from roads, tracks and fencelines. Channels have been created to direct this runoff towards the paddocks with the waterspreading banks, further adding to the water being provided to these increasingly productive paddocks.
These improved areas across Gilgunnia are more reliable in pasture production in deteriorating conditions, and are more able to retain groundcover and protect soils against seasonal impacts.
IMPLEMENTING AN INTENSIVE GRAZING SYSTEM
- After erection of the TGP fence, feral goats within the area are removed
- INS removed and water spreading banks constructed (in selected paddocks and as resources allow)
- Initial rest period of up to 12 months allows existing pasture to recover
- First grazing is timed according to plant germination to ensure desirable species have the opportunity to seed
- A longer rest period after first grazing allows all juvenile plants time to establish and also give mature plants extra resting time
- Then grazed at different times of the year, always allowing for germination of preferred plant species
- Paddocks are grazed two or three times per year to 40-60% pasture utilisation
4 A. McMurtrie, J. Sandow, and P. Theakston (2010), A comparative analysis of two feral goat management methods commonly used in the Cobar districts to restore native ground cover
SUMMARY OF COSTS
The capital required came from the McMurtrie’s own savings, cash flow from the harvesting of feral goats together with cost-share incentive funding from the Western CMA.
- TGP fencing: approximately $4000/km.
The McMurtries have erected approximately 60 km of TGP fencing. Some of these costs have been partly subsidised by works undertaken in partnership with the Western CMA.
- TGP trap yards: average $7000 each.
These have been constructed at ten waterpoints, involving full TGP fencing around the ground tank, trap gates, yard and ramp.
- Water-spreading banks: Total of $12,000, averaging around $950/km or $85/ha.
The length of banks varies depending on the landscape. Construction across two paddocks of 140 hectare total was 12.6 km.
- Troughing: $950 per pump, $300 per tank for fittings, $800 per trough, $1100/km for 50 mm polypipe.
- Land clearing: Depends on INS density and property location. Up to $150/ha, if contracted.
Ashley has cleared some land himself at a third of this cost.
- Machinery: $60,000 for purchase and equipping of machinery to implement changes, including a front end loader and TGP fencing equipment.
The training the McMurtries have participated in has largely been undertaken with the financial assistance of various government entities. The major costs to Ashley and Carolyn have been in regards to time. Ashley has found that accessing expert advice along the way has helped to avoid costly mistakes.
If starting again, Ashley notes that they would spend finances differently, focusing firstly on those factors that produce better results. For example, this would have included more strategic fencing, constructing broader scale perimeters first to reduce the per-hectare cost.
BUILDING A RESILIENT LANDSCAPE
Active decision making and innovation in management can restore the landscape towards its previously productive and resilient state.
The management practices applied on Gilgunnia have transformed the property from a district average situation of declining natural resources, trading terms and infrastructure into an enterprise with increasing productivity and a focus on higher value products. This has been because the McMurtries understand the effects that land management practices have on ecological function of landscapes and the integrity and productivity of native vegetation. This has resulted in a dual outcome: increasing economic resilience and increasing the capacity of the property as a whole to handle seasonally dry times and multi-year droughts.
Ashley disagrees that the landscape is ‘fragile’ as is often claimed. Instead, being long subjected to overgrazing and over-utilisation has left the landscape vulnerable to seasonal changes and climatic conditions. Ashley has demonstrated that active decision making and innovation in management can restore the landscape towards its previously productive and resilient state.
Effective management of TGP maintains groundcover, minimises soil loss, maximises rainfall capture and infiltration, protects the potential to grow forage and enables the managed grazing of wildlife and livestock to produce quality products. It is the combination of intensive TGP control and planned rotational grazing – allowing pasture the time to rest and recover – that has delivered such dramatic results on Gilgunnia.
Ashley notes that the primary ‘resilience’ he has achieved has been the security obtained by having one paddock he can always rely on. Initially this was the first trial paddock, and now more of the intensively managed paddocks as they are developed. Pasture biomass can be banked for future use. Having a few smaller but more reliable areas of pasture provides the opportunity for weaning or fattening stock and offers some resilience to changing conditions. As these areas increase in size it should allow for a considerable increase in stocking rate and even greater flexibility in dealing with varying conditions.
Ashley believes that developing a proportion of any property as an intensive grazing area should provide positive economic and environmental outcomes from a small beginning, especially when developed in conjunction with larger TGP control paddocks.
The property is no longer dependent on the vagaries of the feral goat meat market for survival. Today Gilgunnia is producing high quality Dorper ram replacements and fat lambs with a premium value. To the future, options exist for agistment-based enterprises in the extensively managed component of the property as well as the potential for ecotourism through birdwatchers seeking to spot uncommon species.
Gilgunnia now offers an alternative enterprise model to the district average that is less dependent on season-to-season variation and has inbuilt feed reserves as buffers for dry times. Ashley has observed that stock can be maintained in a healthier condition due to the higher abundance of palatable perennial grasses.
Planning and management is now much easier as feed usage can be budgeted, confident that spelled country will not be grazed out by feral goats and kangaroos in the absence of domestic stock.
The improved carrying capacity on Gilgunnia provides clear evidence of the production benefits of building a diverse and healthy landscape. Ashley and Carolyn have achieved a four-fold increase in productivity, running 900 DSE on 2000 hectares of their property, in comparison to the initial assessment by LHPA of a 1400 DSE carrying capacity on the then 13,000 hectares (ie, 2.2ha/DSE compared with 9.3DSE/ha).
Using the trap yards to capture the feral goats is very efficient. After the initial investment they only require a small amount of money and time to maintain. Depending on the market, goats can bring between $0.70 and $1.00 per kilogram. The density of rangeland goats varies quite widely throughout the Western Division. Local knowledge and a reasonably accurate estimate of the goat density should allow other farmers to discern whether or not this method is suitable for use as a funding source for property development.
Key to the value of the trapping performed on Gilgunnia is that it is used as an income stream to re-invest into the property to ultimately remove the goat population through TGP fencing and replace the grazing pressure with higher value Dorper stock. Commonly seen as a ‘free’ resource in the region, the challenge with feral goats is that the ongoing damage they cause to the natural resource base is rarely acknowledged or calculated.
The change in pasture management is most evident in the intensively grazed system, through the capacity to spell areas for significant periods then stock intensively to a trigger point determined by the level of utilisation of key perennial species. Improved groundcover and perennial species resulting from control of TGP and planned rotational grazing have significantly improved landscape stability and capacity to generate pasture growth.
No vegetation has been sown or planted on the property, and all regrowth is a result of natural seed banks contained within the soil. Desirable species regenerating include red-leg grass, hairy panic (Panicum effusum), cane panic (Panicum subxerophilum), finger panic grass (Digitarias coenicola), curly umbrella grass (Digitaria hystichoides), wallaby grass (Austrodanthonia spp.) and Minnie Daisy (Minuria tridens).
DPI research validating the outcomes of the intensive system has now been presented to several natural resource management conferences and has been submitted to peer-reviewed journals 5Society for Ecological Restoration Rangeland Conference Kununurra WA 2012; 5th World Conference on Ecological Restoration, Wisconsin USA 2013. In comparison to average district management of areas with open continuous access by unmanaged grazers plus domestic stock, the study showed the intensively-managed system has:
- twice the groundcover
- twice the species diversity
- six times the biomass (average standing dry matter on paddocks managed with total grazing pressure control of 800 kg/ha, compared with 125 kg/ha on a paddock on an adjoining property managed without total grazing pressure control) 6C. Waters, G, Melville, A. McMurtrie, W. Smith, T. Atkinson, and Y. Alemseged (2012), The influence of grazing management and total grazing pressure fencing on groundcover and floristic diversity in the semi-arid rangelands
- notable improvement in the abundance of palatable perennial grasses
The drainage flat areas that formerly supported less than 5% groundcover (including leaf litter) and 125 kg of biomass per hectare now support 70% groundcover and a yielded between four and five tonnes of biomass per hectare prior to grazing in April 2014.
These results have been achieved during a period when seasonal conditions have been adverse and stocking numbers have been increased.
The ability to manage access to water through the construction of trap yards has also contributed to improved vegetation condition in the extensive grazing system. However, improvements within the extensive system have been slower since the control of unmanaged grazers is less effective. Gradual development of TGP fencing will improve this control.
Maintaining high levels of groundcover has resulted in obvious improvements in soil characteristics especially on the broad drainage flats throughout the intensively managed system. This has been validated by DPI investigations. Core samples revealed perennial grass root systems penetrating to a depth of more than 1.2 metres.
Higher levels of groundcover and resultant organic matter in the soil brings a substantial improvement to rainfall infiltration and retention. Now light rainfalls, which previously would have evaporated or failed to penetrate the bare soil, are able to be captured where they land. Even during drought small, scattered showers are received, and the ability for plants to make use of this moisture greatly assists their resilience and capacity to survive in these times.
Improved infiltration across the property has now reduced runoff to the point that less water is being collected from surface flows into ground tanks. As the remaining 8000 hectares of Gilgunnia are regenerated, this will have to be monitored carefully to ensure that sufficient ongoing stock water supplies will be available.
Land management innovations on Gilgunnia have resulted in a healthier landscape with more biodiversity – which delivers increased resilience. The grazing system has demonstrated a substantial shift in native pasture species composition and the re-establishment of grassland biota, especially in relation to birdlife. In areas where invasive native scrub management has resulted in more open landscapes and improved grassland habitat, the grasslands have attracted a range of seed-eating species such as quail. Concurrently there is a change in the balance of predatory species with a notable increase in the abundance of small raptors. The return of top level predators is seen as an indication of improving biodiversity. Thick shrubby landscapes appear to favour stealth based predators such as foxes, whereas the more open grassy areas are known to carry a much higher biomass providing habitat for small ground dwelling animals including insects, arthropods, reptiles and mammals and a hence increased diversity for foraging raptors.
A recent survey identified eight species of raptor within the intensively managed area, including sightings of the endangered grey falcon. There is evidence of two pairs of these rare falcons on the property. These raptors were absent prior to improved grazing management. DPI has contracted a formal biodiversity survey in late 2014 to examine these changes.
PERSONAL & SOCIAL OUTCOMES
On the personal front, the McMurtrie family has gained much through the learning and property development process they have undertaken over the last decade.
They now have a greater understanding of the ecological function of landscapes and how land management practices can be used to improve the integrity and productivity of the native vegetation. This understanding has given them greater confidence in decision making as outcomes are more predictable.
They have developed a solid network of innovative natural resource management professionals and are easily able to access knowledge, education and greater experience. These lasting friendships with like-minded people support free information sharing. Ashley and Carolyn have an open policy on information and access to their improvements in order to expand the community understanding of rangeland management systems and options.
Overall, Gilgunnia is now a more enduring and successful local business. The family experiences more stability and less stress as the business is more reliable – and there are only further improvements to come.
REGENERATION FOR RESILIENCE
Ashley and Carolyn McMurtrie moved into the Western Division with no pre-conceived ideas on how their property should be managed. This perhaps, gave them the unfettered opportunity to investigate best-practice in landscape management.
What they learnt along the way was that what was best for production was also best for environmental regeneration – and building a landscape that is resilient in the face of seasonal and multi-year droughts and other climatic extremes.
Now the McMurtries provide a case study of what can be achieved in the highly variable environmental conditions of the Western Division, hopefully for others to now learn from and follow.
In Ashley’s words:
The process we have undertaken over the last nine years has taken our business from a struggling opportunistic feral goat harvesting business that was completely exposed to seasonal conditions to a business that is far more resilient.
We have now developed and continue to expand a dual system business with high value stock that is dynamic in seasonal conditions, and is continuing to develop under its own financial success, with documented increases in groundcover, biodiversity and biomass. This has occurred during a period in which we had only 2 years of average or above rainfall. The majority of profit each year is directly put back into expanding these systems and will be for the next 5-7 years in order to create TGP control over the entire property. Without the development and success of this model we would have remained in a financially static position, with no domestic stock and still completely exposed to seasonal rainfall variation.