Salisbury: Rehabilitating the Scalds

Salisbury: Rehabilitating the Scalds

A regenerative agriculture case study from The Marra, north-central NSW.

In the 1980s, portions of Salisbury were fit for one thing and one thing only: landing an aeroplane. Since then, the MacAlpine family has rehabilitated much of this scalded land and developed a number of strategies to make their property ready for both the droughts and flooding rains that this part of the country is prone to.

ABOUT SALISBURY

The Property

The Salisbury property is located on the floodplain and associated relict red duplex terraces of the Marra Creek, to the west of the Macquarie Marshes about 160 km north-west of Warren in north-central New South Wales. The Queensland border is about 160 km further north. Carinda – the nearest town – is about 60 km north-east. Marra Creek runs through the region. It adjoins Salisbury on the property’s western side and potentially flows north into the Barwon River, a tributary of the Darling River.

Salisbury is about 20,000 hectares. The MacAlpines consider that area can support a self-replacing merino flock totalling about 10,000 dry sheep equivalents, typically comprising 5000 breeding ewes (1.5 DSE each) and 2500 ewe lambs, on average in the long term (and allowing for the kangaroos!). The property is subdivided into 22 main paddocks and a few holding yards and transport routes.

Salisbury was previously part of the Womboin Station, which was owned by the Dalgety company. Womboin was subdivided in 1972. The MacAlpine family purchased the Salisbury part in 1977 and added two adjoining blocks soon after. Half of Salisbury is on dark heavy clay soil that is relatively impervious to erosion. This rest is red soil that has a better natural potential for grazing has been degraded by wind and water erosion.

FARM FACTS

Salisbury, The Marra, NSW

ENTERPRISE: Self-replacing merino flock

PROPERTY SIZE: 20,000 hectares

AVERAGE ANNUAL RAINFALL: Approximately 450 mm

ELEVATION: 133 m

MOTIVATION FOR CHANGE

  • Improve the health and condition of the sheep, primarily through improving the health and condition of the pastures

INNOVATIONS

  • Reclaiming scalded red duplex country through “waterponding”
  • Manage total grazing pressure with wildlife-proof fencing
  • Manage sheep numbers via trigger point assessments at key points in the annual cycle
  • Manage water infrastructure
  • Supplementary feeding to assist breeding

KEY RESULTS

  • Approximately a quarter of the property (most of the scalded red country) has been treated with waterponds.
  • Several paddocks have been enclosed with wildlife proof fencing.
  • Sheep numbers are being managed via decisions on numbers to join and disposal to sale or to brother’s property at Grenfell, NSW.
  • Three of the four artesian bores on the property have been capped and piped to tanks – each with two troughs.
  • Supplementary feeding infrastructure established.


THE ECOLOGICAL ASSESSMENT

All functional criteria in are considered to have improved since 1972. For example, since the widespread adoption of regenerative practices in 2009:
• the property is becoming more resilient to drought. A similar conclusion is likely for flood proofing
• soil health and function has gradually improved
• vegetation biodiversity has stayed much the same during the waterponding operations
• pasture status has gradually improved (from zero) in the ponded areas, due to increased ground cover and herb species richness.
The reproductive potential of the plant species and plant community has similarly improved.
More improvement in these values is expected in future, particularly when drought conditions ease. Further rainfall will serve to leach salts from surface layers of the scalds as well as provide an essential input for plant growth.


THE SOCIAL REPORT

The MacAlpine vision for regenerative agriculture developed and evolved over many years of experience to meet perceived needs of the family and their country. Their broad aim is to remain profitable while not degrading (or, where possible, improving) their asset base and its resilience to drought. Their early grazing practices noticeably degraded the country and its resilience, so they were always on the lookout for better ways of managing their stock and country.
Grant made all management decisions in the early days. Will is now joint manager with a focus on the stock. Strategic decisions for Salisbury are made by Grant, Cathy and Will at weekly meetings. Rather than a formal risk management framework, the family makes judgements based on the accumulated wisdom gained from years of experience on the property and the experience of neighbours.


THE ECONOMIC REPORT

The regenerative farming practices that the MacAlpines have implemented on Salisbury have led to significantly increased production levels when compared to the Average Farm. With increased productivity, the income generated on Salisbury is also significantly higher than that of the Average Farm.


Tour the farm with Will MacAlpine

Ready for drought, ready for rain

Salisbury is typical of Dorothea McKellar’s ‘land of droughts and flooding rains’. There are no permanent watercourses on Salisbury. Water supply is rain and bores that tap the Great Artesian Basin. Average annual rainfall is about 450 mm on the property or 405 mm as measured at the nearest meteorological station, perhaps indicating high local variability. The average and median monthly rainfall sometimes falls in a single day, sometimes causing regional flooding. Conversely, very little rain falls for substantial periods.

Will MacAlpine is clear that for the grazing business to cope, obtaining maximum benefit from rainfall events and minimum damage during dry periods, ‘we must be ready for drought, and we must be ready for rain’. The strategy to achieve that comprises a number of tactics:

  • Increase the area of productive grazing land by rehabilitating scalded land.
  • Cap the artesian bores to control water supply.
  • Control kangaroo grazing pressure.
  • Manage sheep grazing pressure in dry periods by moving sheep to holding pens and hand feeding them, and by deferring joining young ewes.

In practice, these tactics are interlinked or interdependent.

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Rehabilitating the scalds

A scald on Salisbury, still remaining in 2020, showing the hard-packed surface soil and elevated root systems of dead plants, indicating the depth of topsoil lost to wind and water erosion.

Although rehabilitation work was begun on Salisbury in the 1970s by the previous owners, when the MacAlpines took over the property Grant MacAlpine could land his light plane almost anywhere on the property. After seeing promising results on properties nearby, the MacAlpine family continued rehabilitation in the 1980s and 1990s. Works ramped up in 2009 and 2012 when government grants were available.

The methods that have been used successfully for several years on Salisbury involve using a grader to build low ponding banks to hold rainwater to a depth of 10 cm or so. These are circular on flat ground and semi-circular (a ‘horseshoe’ shape) on scald with a mild slope. The opening of the horseshoe is to the up-slope side, so that run-off collects within the banks. Each pond covers about 0.4 hectares. The grader used to construct the banks is also used to disturb the soil surface within the ponds in strategic locations (Thompson 2008). Saltbush seed – some of it collected on the property – is sown over the disturbed surface. Running cattle over the ponded area after the surface had been softened by rain was used to disturb the soil surface in a previous Soils For Life case study of a property near Brewarrina.

The effect of the ponding banks and disturbance is to hold water from the intermittent heavy falls. This then infiltrates – albeit slowly – to leach salts from the surface and provide moisture down the soil profile. The banks and disturbance within them provide a barrier to wind-blown sediments and plant material, which collects and starts to form an organic-rich surface layer. The saltbush seed, together with whatever seed is delivered by wind, sheep and birds, then has somewhere to germinate and moisture to tap in the soil profile. The natural processes of ecological succession have effectively been given a ‘kick-start’ and can take their course. To date, about half of the scalded areas on Salisbury have been treated in this way.

The results can be seen here:

Capping the bores

Four artesian bores that were installed early in the 20th century and have been flowing ever since supplement Salisbury’s intermittent water supply from rainfall. The aggregate potential flow rate is 9 L/second (284 ML/year, or about 114 Olympic swimming pools). However, the volume required to support grazing stock is estimated at around 1 L/second, so the rest (around 250 ML/year) runs away to waste via bore drains. The wasted water supports a kangaroo population far in excess of what would be there naturally, whereas a tank and trough system can be managed to restrict water supply.

Bore drain
One of the four bore drains that together used to carry away around 250 Ml/year of surplus water.

Capping the bores maintained the pressure of the underground artesian aquifer and used only the amount of water needed for stock. A threat by governments to charge for water used in excess of stock requirements focused the MacAlpines’ action. A subsidy from the NSW Government [1] helped too. Following the mandated specifications, each tank supplies two nearby troughs – the second being presumably for backup in case one failed. So far, two of the four bores on Salisbury have been capped.

tanks and troughs
Tank and troughs that have replaced free-flowing artesian bores.

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Managing grazing pressure

This is the biggest concern for the viability of the Salisbury business is a seemingly endless supply of kangaroos willing to move on to the property. Generally, they come from the north and arguably in far higher numbers than would have been possible before graziers started providing water sources.

Managing the kangaroo population requires a massive investment in specifically designed fencing. Fences like that will also exclude wild dogs that be-devil sheep graziers elsewhere and that the MacAlpines expect in the Marra region before long.

The cost of kangaroo-proof fencing is around $4,000/km for materials and the property boundary is about 50 km, so a substantial investment is required. Fortunately, the NSW Government has provided a low-interest loan for this.

Kangaroo proof fence
Kangaroo-proof fence: extra height wire supported by fewer posts; mesh apron to prevent kangaroos pushing under the bottom wire; two electrified mid height wires powered by solar panels.

Sheep grazing pressure is managed in dry periods by moving sheep to holding pens and hand feeding them with grain and straw. This is especially useful for ensuring that ewes chosen for breeding have optimum nutrition.

Further tactics to reduce grazing pressure include:

  • deferring joining young ewes so that their grazing requirements are minimised; and
  • selling older ewes or passing them on to the farm run by Alex MacAlpine at Grenfell, NSW.

Will and Grant MacAlpine make these decisions from time to time [2], taking particular note of animal and pasture health.

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Adapted to a variable climate

In summary, the grazing enterprise at Salisbury is well adapted to the highly variable, semi-arid climate. Amongst their many benefits, the water ponds bring more areas into production and generally improve the appearance of the property. Capping the bore, erecting wildlife-proof fencing and managing stock numbers controls the total grazing pressure and ensures sustainability so that the MacAlpines are ready for drought and ready for rain.


[1] Not as generous as the subsidy in Queensland.

[2] Especially over the summer period when a “feed gap” would develop if rain was inadequate.

References

Cunningham, G.M. 1987. Reclamation of scalded land in western New South Wales. Journal of Soil Conservation New South Wales, Vol. 3, number 2. Soil Conservation Service of NSW, Sydney.

Rhodes, D. 1987. Waterponding banks – design, layout and construction. Journal of Soil Conservation New South Wales, Vol. 3, number 2. Soil Conservation Service of NSW, Sydney.

Herczeg, A.L. and Love, A.J. 2007. Review of Recharge Mechanisms for the Great Artesian Basin. CSIRO Land and Water, Glen Osmond, South Australia.

Thompson, R. 2008. Waterponding: Reclamation technique for scalded duplex soils in western New South Wales rangelands. Ecological Management and Restoration 9: 170-181. doi: 10.1111/j.1442-8903.2008.00415.x

Are you our next case study? If you have a story of change to tell about your regenerative landscape practices we’d love to hear from you! Find out more here.

The 10 things our ecologists look at when conducting field visits on farms

The Soils For Life team provides professional assessment of properties that are using regenerative landscape management practices. Our case study program considers the quadruple bottom line of each property by looking at the effects of regenerative agriculture practices on a farm’s production, economics and ecology as well as the social implications of these practices.

As well as conducting extensive desktop research, our ecologists conduct field trips to assess first hand the impacts of regenerative agriculture on the ecology of the farm. They chose ten criteria to represent the regenerative and productive capacity of each major land type on a farm.

Here are the ten things that they are looking at when they visit a farm:

Image from our case study Jillamatong

1 – Resilience to major natural disturbances

Resilience to major disturbances includes the following factors depending on the agro-climatic region (wildfire, drought, cyclone, dust storm, flood, frost). A major natural disaster or natural disturbance event can occur at any time. Some disturbances give a warning, such as a windstorm or electrical storm preceding a wildfire or a flood. Once a disaster happens, the time to prepare is gone. Lack of preparation can have enormous consequences on farm life including social, ecological, economics and production.

2 – Soil nutrients including soil carbon

Soil organic matter (SOM) plays a vital role in influencing available soil nutrients. Generally for every tonne of carbon in SOM 15 kg of phosphorus, 15 kg of sulphur and about 100 kilograms (kg) of nitrogen become available to plants as the organic matter is broken down. It is vital to know how much carbon we have in soil so that we can roughly estimate the potential supply of nutrients. SOM releases nutrients for plant growth, promotes the structure, biological and physical health of soil, and is a buffer against harmful substances.

3 – Soil surface water infiltration

Soil texture and structure greatly influence water infiltration, permeability and water-holding capacity. Of the water entering a soil profile, some will be stored within the root zone for plant use, some will evaporate, and some will drain away. In agro-ecological settings, by increasing water infiltration, permeability and water-holding capacity this will usually act as a stimulus to improve ecological function. Management regimes that promote the capture and utilisation of rainfall where it falls generally enhances ecological function.

4 – Biological activity in the soil

Soil biology affects plant and animal production by modifying the soil physical, chemical and biological environment within which plants grow and persist. The ratio of fungi to bacteria is important for land managers to understand – too many bacteria can indicate an unhealthy and unproductive soil.

In healthy soils, there is a good balance between fungi and bacteria; invertebrates including arthropods and worms are usually present. Collectively these form a vital part of a plant nutrient supply web.

A wetland from our Fairhalt case study

5 – The physical properties of the soil

Soil is a medium for plant growth, given the right environmental conditions. In some agroclimatic regions, the naturally occurring surface layers (A horizon) have historically been adversely impacted by inappropriate land management regimes. Major and moderate loss of the A horizon either through water or wind erosion may have diminished the ecological function of the soil as a medium for optimal plant growth.

6 – Changes and trends in the reproductive potential of plants

Grazing production systems rely on an ecosystem’s inherent capacity to bounce back after grazing and natural climate events (e.g. wildfire and drought). Where regenerative land management regimes have been implemented to build or rebuild the reproductive potential of plants and pastures, we look at the observed outcomes on plant/pasture reproduction, germination, establishment, development and maintenance.

7 – The extent of tree cover

Tree cover in agricultural landscapes provides important ecosystem benefits, including mitigation of soil erosion; shelter for pastures and crops; improved animal welfare; enabling added revenue from stacked (multiple) enterprises; habitat and breeding sites for pollinators and predatory insects birds and animals; improved salinity management; improved interception of rainfall; and improved aquifer recharge.

8 – Status of ground cover

Ground cover in agricultural landscapes provides important ecosystem benefits. The quality of ground cover provides essential protection to keep the soil cool against direct, searing summer heat by reducing evaporation and protecting bare soil against raindrop splash and wind erosion. A dense, matted ground layer of pasture grasses slows overland flows during the intense rainfall events and assists with infiltration of rainfall, thus mitigating soil erosion and replenishing soil moisture. Ground cover also provides essential habitat and breeding sites for pollinators and insects and birds and other biodiversity. Land management regimes that promote higher levels of ground cover and biomass in critical growing seasons generally enhances ecological function.

9 – The diversity of tree and shrub species

Intensively managed agricultural landscapes typically adopt management regimes that simplify the diversity and number of species of trees and shrubs for pasture and crop production. Where regenerative land management regimes have been implemented there has been an observed increase in the number of tree and shrub species.

10 – The diversity of grass species

In many grazing production systems, the implementation of regenerative land management regimes can improve the variety of pasture plants (annuals and perennials). In turn this can improve pasture production, animal nutrition, protect natural resources (soil and water) and build the capacity of farming systems to adapt to future production and environmental challenges. The intensity of the grazing management system will determine the health and vitality of pastures and their longevity.

The management and selection of the perennial pasture species for a grazing production system should be based on considerations of climate, soil conditions and performance of pasture species under different management regimes.

Read about how land managers have improved each of these ecological criteria on their farms in latest case study reports. You can search them by state or sector here.

Are you farming using regenerative agriculture practices? Why not consider applying to be a case study.

CEO’s Report

from Acting CEO, Narelle Luff.

It has been my pleasure to support the Soils For Life team whilst we seek a new CEO. It hasn’t always been easy with my new (home) office also being a school and childcare centre!

The view from my new office!
Kangaroo grass thriving in my backyard after Canberra’s autumn rain

During the COVID-19 lockdown the Soils For Life team has been finalising case studies commenced before travel and social distancing measures were implemented. Salisbury is the last of these to be published.

The team has also been working to design a comprehensive evaluation plan for the case study program and we have been looking at ways we can develop education resources to support learning. We hope these resources will act as a catalyst for you to take some action on your property or to seek a new path of professional development through further reading or training.

The team at Soils For Life are relieved to see some changes to the travel and work restrictions and we expect our field teams will soon return to farm visits. We will continue to publish our monthly newsletter however over the coming months instead of publishing a new case study with each newsletter we will republish a previous case study and alongside this we will publish an education resource.

It is our plan to develop field days for the new case study farms. When there is greater certainty about social gatherings we will start scheduling these events. We will keep you informed via our website, newsletter and our socials.

Finally, we have revised the case study program application form. We value feedback from our audience and case study participants and have taken the opportunity to simplify the application form after speaking with farmers. Learn more about being a case study participant here and find the application form here.

Our team are here to help, so if you want to have a chat or want some assistance to complete the application give us a call.

Narelle Luff

Operations Manager / Acting CEO

Meet Katharine Brown

Katharine Brown recently joined the Soils For Life project team, bringing with her a wealth of knowledge and curiosity about soils. We asked her what she finds most fascinating about soil in this Q and A.

Q: What do you find so fascinating about soil?

A: There are an infinite number of fascinating facts about soil! If I were to choose one, it would be that “each soil has had its own history. Like a river, a mountain, a forest, or any natural thing, its present condition is due to the influences of many things and events of the past.” That’s a quote by soil scientist Dr Charles E. Kellogg from 1938. When you observe a soil, you gain an understanding of its past (how it formed), its present (how it functions), and its future (how it responds).

Q: You’ve been a soil scientist for 20 years now. What has been the most exciting thing/change you’ve seen in your career?

A: I am encouraged by the growing consensus on the significance of soils and the value of soil information. In particular, the recognition that soil is a finite natural resource and that soil condition will determine the extent society, the nation and the planet will benefit from ecosystem services. I am equally encouraged by the increase in the number of women soil scientists in what continues to be a male-dominated profession.

Q: What’s your new role with SFL and what will you be doing?

A: As a Soils For Life Project Team Member, I will be researching the benefits of regenerative agriculture on the soil, encouraging the adoption of land management practices to improve soil condition, sharing soil science knowledge with my colleagues, community and regenerative farmers, and increasing my understanding of regenerative agriculture practices.

Q: What’s one myth about soils you’d like to see busted?

A: That the “magic” happens in the topsoil. To understand the past, present, and future of a soil, we need to dig deeper!

Q: If you could change one thing about how people think about soil what would it be?

A: I would like to dispel two common thoughts:

1. That we can take from the soil without giving back.

2. That soil is dirt. Dirt is inert. Soil is alive.

Read more about the expertise on the Soils For Life team here.