Mallee Forage Shrubs Decision Tree

A tool for the management and enhancement of forage shrubs

Welcome to our Forage Shrubs Decision Tree!

Perennial forage shrubs, or mixtures of forage shrubs and pasture, can provide a highly productive, complimentary grazing resource on mixed farms in southern Australia. Benefits span both livestock production and natural resource management, since plantings not only add to the resilience of the feed base, but also improve biodiversity and helping protect or reclaim degraded land.

There are many different ways that forage shrub planting can be set up and managed. For example, farmers may choose to grow one shrub type or many, in either alley or block plantings, with or without pasture in the inter-row space.

Many farmers in the NSW, Victorian and SA Mallee regions have already planted saltbush, but are interested in improving the way they manage it. Other farmers may be new to forage shrubs but aren’t sure how to go about it. This decision tree has been set up to guide individual farmers towards planting designs and information that best suits their situation.

1. Is your main interest to improve an existing saltbush planting?

There are many plantings of saltbush in the Mallee that have survived over 20 years, but have become too dense and overgrown, sometimes providing habitat for rabbits. In some cases livestock have not performed as well as expected on the forage. This decision pathway explores how to rejuvenate existing plantings and better manage grazing of shrubs.

2. Is your main interest to rehabilitate saline or erosion prone ground, and improve biodiversity?

There are areas on many farms that are not profitable for cropping – these areas may be showing early signs of salinity (discharge area), have subsoil constraints, or be at risk of wind erosion. Rather than writing off these areas or letting them further degrade, they can be regenerated with forage shrubs. Shrubs have also been shown to have biodiversity benefits.

3. Are you primarily interested in improving whole farm feed stability and/or extra shelter for stock?

The resilience and perenniality of forage shrubs creates a more stable feed supply, especially during dry seasons, which can be used to fill feed gaps defer autumn grazing to so feed can ‘get away’. They also provide a rich source of protein and minerals, and shelter from extreme weather.

Shrubs Decision Tree

What is your primary interest in forage shrubs?

Is your main interest to improve an existing saltbush planting?

Is your main interest to rehabilitate saline or erosion prone ground, and improve biodiversity?

Are you primarily interested in improving whole farm feed stability and/or extra shelter for stock?

1.1 What are the characteristics of your existing Old Man Saltbush?

Old man saltbush can grow tall and wide, causing a greater proportion of new shoots growing beyond grazing height, or producting impenetrable hedges. Other scenarios include a reduction in edible biomass and potential feed for livestock.

Are the shrubs are too dense and overgrown?

Would you like feed utilisation and livestock performance can be improved?

Outcome A+B (1B + 2A)

Based on your decisions above, there’s two suggested actions that you could take. These are displayed below.

Action option 1

Improve stand by pruning, removing rows and establishing inter-row pasture

Pruning: Overgrown saltbush plants can be successfully pruned back to an ideal size to stimulate new growth accessible to sheep.

Removing rows: Shrubs planted too densely are less productive due to increased competition between shrubs. Rows can be removed to allow better pasture growth and access for stock and machinery.

Companion Pasture: By creating more room between saltbush plants, inter-row pasture can be better managed.

Action option 2

Refine grazing management and use of supplementary feeds

Annual grazing: To get the best out of forage shrubs, it is important to graze at least annually, and in years of plentiful growth twice a year.

High-density stocking: Stocking densities need to be high to promote even grazing. This usually means that shrubs need to be fenced and paddock size needs to be small.

Train stock to eat shrubs: Sheep that are not used to shrubs need to be introduced to their new diet gradually – a small number of positive, low stress experiences are required to change grazing behaviour.

Outcome C (1B)

Based on your decisions above the suggested action that you could take is displayed below.

Refine grazing management and use of supplementary feeds

Annual grazing: To get the best out of forage shrubs, it is important to graze at least annually, and in years of plentiful growth twice a year.

High-density stocking: Stocking densities need to be high to promote even grazing. This usually means that shrubs need to be fenced and paddock size needs to be small.

2.1 What are the characteristics of your rehabilitation zones?

In many cases, areas of lower productivity are irregular in shape and located in various pockets around the farm. However, if the areas to be rehabilitated are substantial and can be treated as one management unit, or several management units, it influences the planting design used, the importance of companion pasture and also the opportunity for them to be used as part of the whole farm feedbase.

Are your areas are small, irregular shaped and isolated?

Are your areas substantial?

2.2 Are you willing to use rotational grazing techniques to improve utilisation of different types of feed?

Grazing at least annually, and in years of plentiful growth twice a year, will keep shrubs short and productive. Grazing with cattle and older experienced sheep to ‘finish up’ shrubs which have grown out of reach of smaller animals is also a useful option if available.

Yes, I would like to implement grazing management techniques.

No, it is not suitable for me to implement grazing management techniques.

2.3 Are your areas able to or have the potential to support pasture growth?

Ensuring good pasture is essential for preserving ground cover, particularly in low-productivity areas. While the main goal is to regenerate or improve these areas using forage shrubs, they can still serve as a valuable feed source for livestock, primarily through understorey pasture.

No, grazing small paddocks of different shrubs and pasture, and shifting stock every 1-3 weeks, would not suit my situation.

Yes, I am prepared to rotate stock every 1-2 weeks through small paddocks containing different feeds at high grazing pressure

Outcome D (3D)

Based on your decisions above the suggested action that you could take is displayed below.

the area does not support pasture growth

Establishing blocks of forage shrubs on salt-affected or eroded sandy soils

Many farms in the Mallee contain saline areas that do not support pasture growth. Forage shrubs can play an important role in remediating these areas by using more water, slowing wind speeds, or providing ground cover during dry months.

Action: Establish blocks of saltbush

Where shrubs sites cannot support pasture growth, shrubs are established in blocks
Farmers typically use Old Man Saltbush but also consider newer varieties like Anameka and Eyres Green that are more productive but don’t self seed. Consider River Saltbush on waterlogged saline sites, or Mallee Saltbush on very sandy sites.

Outcome E (4E)

Based on your decisions above the suggested action that you could take is displayed below.

the area can support pasture growth

Establishing a shrub-pasture mixe

Many Mallee farms have areas of land that are unproductive for cropping but will still support forage shrubs and some level of pasture production. In this situation, the under-storey pastures provide the bulk of the feed on offer, and the shrubs provide a complementary source of crude protein and minerals.

Farmers typically use Old Man Saltbush but also consider newer varieties like Anameka and Eyres Green that are more productive but don’t self seed. Consider River Saltbush on waterlogged saline sites, or Mallee Saltbush on very sandy sites.
Shrubs can be established in blocks or alleys
With alleys, consider the width needed for machinery access down the inter-row so that grazing crops or pastures can be sown.

Outcome F (5G+6H)

Based on your decisions above the suggested action that you could take is displayed below.

diverse shrub plantings, with or without inter-row pasture

Establishing and managing diverse shrub-pasture and forage shrub plantings in the Mallee

The nutritional needs of grazing livestock vary significantly overtime, both between years and within the year. Providing livestock with a forage mix comprised of different plants, each with their own unique combination of nutrients and minerals, increases the chance of fulfilling the requirements of animals during many differing scenarios and potentially reduces the need for supplements. Total feed intake usually increases with additional plant species on offer — when an animal consumes its limit of one species, it may still consume another species with a different balance of nutrients.

Historically few forage shrub species have been grown on a commercial scale in Australia besides old man saltbush. However, recent research from the Enrich project has revealed a number of species which, when used together, can be productive and persistent in the low-rainfall zones of southern Australia.

Selecting companion pasture species and cultivars for use in a shrub-based system varies little from when growing a stand-alone pasture. Suitability to soil type and rainfall are critical factors.

Correct selection of shrub species depends primarily on soil factors such as salinity, waterlogging and texture. The species making up the mix do not necessarily need to be evenly proportioned. When considering the proportion of each species in a mixed planting, there is no single correct method. The benefits of including a mix will more likely to be found when all species are significantly represented (at least 10% of biomass).

3.1 Are the shrubs to improve whole farm feed stability, or primarily for shelter off-shears or in poor weather?

Forage shrubs, when integrated with well-managed pasture, offer significant potential to fulfill the crude protein and mineral requirements of grazing animals. Additionally, they provide essential shade and shelter, often overlooked but crucial for optimizing animal production efficiency. By reducing wind speed, forage shrubs play a vital role during critical periods such as off-shearing and lambing.

Are the shrubs to improve whole farm feed stability?

Are shrubs to primarily provide shelter for livestock in poor weather or off-shears?

3.3 What are the characteristics of the available land?

To provide livestock with a comprehensive range of nutrients and minerals, a combination of forage plants such as shrubs is recommended. The specific selection of plants depends on the unique characteristics and requirements of your land. By customizing the shrub selection, you can maximize the benefits for your livestock’s health and well-being.

Are your areas are small (less than 3 ha), irregular in shape and isolated

Are your areas are substantial in size (greater than 5-10 ha) and located close to each other?

Outcome G (6H)

Based on your decisions above the suggested action that you could take is displayed below.

Diverse shrub–pasture system in low density blocks

Establishing blocks of diverse forage shrubs.

Many farms in the Mallee contain soils that do not grow productive crops or pastures. With investment in shrubs and fencing, and a preparedness to rotationally graze, block plantings of diverse shrubs can be successfully established and used.

The nutritional needs of grazing livestock vary significantly over time, both within the year and between years.
Providing livestock with a forage mix comprised of different shrubs, each with their own unique combination of nutrients and minerals, increases the chance of fulfilling nutritional requirements and reduces the need for feed supplements.
With investment in shrubs and fencing, and a preparedness to rotationally graze, block plantings of diverse shrubs can be successfully established and used.
Good grazing management is essential to ensure most palatable species are not grazed out first.

Outcome H (5G)

Based on your decisions above the suggested action that you could take is displayed below.

Diverse shrub–pasture system in either block or alley design

Establish shrubs in low density blocks or alleys with pasture grown in-between

Where farmers are primarily interested in improving the resilience of the livestock feedbase, and are prepared to rotate stock through shrub-pasture plantings, they should consider establishing mixtures of diverse shrubs and pasture.

Under-storey pastures provide the bulk of the feed on offer, with shrubs providing a complementary source of crude protein and minerals.
These plantings can not only improve farm productivity and drought resilience, but also improve salinity, erosion and biodiversity outcomes.
The optimal design is likely to be double or triple rows of diverse shrubs separated by alleys that support grazing cereals or sown pastures.
Grazing management is paramount – diverse shrub and pasture mixes need to be grazed at high intensity with stock rotated frequently to ensure all feeds are utilised and no particular species is overgrazed.

Outcome I (7K)

Based on your decisions above the suggested action that you could take is displayed below.

Old man saltbush planted in moderate density blocks

Saltbush planted primarily to provide shelter for livestock.

Where the primary purpose of a shrub planting is to provide feed and shelter for sheep during poor weather, the normal approach is to plant blocks of saltbush

Planting just one kind of shrub gives greater flexibility in how grazing is managed
During lambing, a shrub-based paddock during can also improve lamb survival
Small block plantings near sheep yards are a great way for farmers to make a start with forage shrubs and their management.