How to grow soil organic matter

How to build soil organic matter: Lessons from three different Australian landscapes

Mark Parsons

Most of the soils across Australia contain only a small proportion of organic matter. So it’s not surprising that many farmers think about building up the organic matter in their soil as a cost-effective way to boost productivity as well as reduce input costs. But there isn’t simply a one-size-fits-all way to do it. As these three examples from our case study properties show, methods for building soil organic carbon are as diverse as the landscapes these properties inhabit.

At Clover Estate on the sandy soils of south-east South Australia, the strategy was to inoculate the soil with fungi, bacteria and biologically-derived fertilisers to provide a substrate for microorganisms. Dealing with low and variable rainfall in the wheat belt of Western Australia, the Prospect Pastoral Company used direct sowing of compost-coated grain seed to encourage root growth to contribute to organic matter in the soil. On the Liverpool plains of NSW, Inveraray Downs took an integrated approach using livestock, compost-based fertiliser and crop rotation to achieve their goals. In all cases, as we outline below, the results speak for themselves.

What is soil organic matter?

We frequently hear about ‘building soil carbon content’. That phrase a bit misleading (unless we are actually talking about burying coal or charcoal!) What most people mean when they say this is ‘building soil organic matter’. This used to be commonly referred to as humus – but humus is only one of four components comprising soil organic matter. Carbon is merely one of the many constituents of soil organic matter, where it is inextricably bound up in all sorts of complicated organic molecules.

Organic matter is practically always present in soil. Proportions range from very little (for example, less than 0.5% in a bleached sand soil) to nearly 100% in the peatiest of peats. Peat is decayed plant material that accumulates in bogs where decomposition of the organic matter is inhibited by wet and cold conditions. Australia has plenty of sandy soils, most notably in southern South Australia and in south-western Western Australia. However, we also have vast areas of soils in between these extremes (1% to 4% organic matter is common) that could benefit from higher proportion.

Organic matter contains essential plant nutrients that become available to plants through the action of biochemical processes. These nutrients become available to plants as the organic matter decomposes. Organic matter also holds moisture, which therefore increases soil moisture holding capacity, especially on sandy soils.

What builds soil organic matter?

Wherever plants grow, roots die and decompose in the soil. Plant leaves and stems also die and fall to the ground, where they may be incorporated into the soil by the combined action of fungi, bacteria, insects, other invertebrates (such as worms), and by vertebrate animals that burrow or dig into the soil.

Native marsupials (like potaroos, bettongs and bandicoots) that dig for fungi, roots, tubers and invertebrates both cultivate the soil and help incorporate organic matter. However, most of these marsupials need dense ground cover vegetation as habitat. The lack of that on some farms, as well as predation by cats and foxes, means these marsupials may no longer occur on most farmland.

Manure can be another source of soil organic matter. In the absence of marsupials, dung beetles that help manure infiltrate the soil by burying it provide an important service to agriculture.

Lessons from Clover Estate, South Australia

The Clover Estate farm in south-east South Australia is located on a land system comprising low, wide sand ridges that developed along the coast as sea levels rose and fell over the past several million years. The deep sandy soil has low natural fertility and organic matter. Water supply is good because there is an aquifer not far below that carries ground water from the east. They found they could add enough fertiliser, irrigate, and pasture productivity was good. But such a solution wasn’t cost-effective in the long-run. Building up soil organic matter was seen as the way to reduce dependence on chemical inputs and to improve animal health at the same time.

They inoculated the soil with plant residue-digesting fungi and bacteria together with biologically derived high-carbon fertilisers to provide a substrate for the microorganisms. Over a period of about 10 years these stimulants increased the measured soil organic carbon content from around 2% to 3%. That might not sound like much, but the combined effects were dramatic: pasture vigour and production improved to the extent that stock output increased by 33%. At the same time, chemical weed control was eliminated and irrigation requirement was reduced from 7–8 Ml/hectare/year to 5–6 Ml/hectare/year, so that input costs were significantly lower.

Clover estate organic matter
The results of 15 years of organic-based treatments at Clover Estate are evident in the much darker colour, resulting from higher organic matter content down to 600mm where it used to be devoid of biological activity (right), which means that nutrient and water holding capacity are far higher. Compared with the typical condition of the original infertile sand is indicated by the profile under the patch of remnant native vegetation on the southern edge of the property, where no treatments have been applied (left).

Building organic matter in poor, sandy soil

Similar methods have been applied in the wheat belt of Western Australia by the Prospect Pastoral Company farm at Wyalkatchem, 160 km north east of Perth. Producing wheat here, on the poor, sandy soils that are prevalent, depends entirely on low and highly variable rainfall. Critical to crop production, soil moisture holding capacity is even more important here than in southern South Australia where irrigation is available. Soil organic matter can play an important role in this.

This case study practices direct sowing of grain seed to minimise soil disturbance, which helps maintain ground cover, helps with weed control and avoids loss of soil organic matter. The grain seed is coated with a compost extract that is found to encourage root growth and leads to a healthier and more productive plant. Soil organic matter is also increased by the vigorous root growth. Once grain is harvested, crop stubble is grazed by sheep bred on the property and adapted to maximise nutrient extraction from roughage. Dung and stubble trampled into the ground also leads to increased soil organic matter.

The extensive root growth at Prospect Pastoral Company farm is a sign of a healthy nutrient system.

Integrated approaches on Inveraray Downs

Building soil organic matter has also proved valuable in the quite different landscape on the deep clay soils of the Liverpool plains, north-eastern New South Wales. Soils For Life case study property Inveraray Downs is a grain production property, growing crops such as wheat, sorghum, corn, sunflower and barley. Since the ‘green revolution’ of the mid 20th century, the introduction of higher-yielding varieties of these sorts of grains was associated with considerably increased use of chemical fertilisers and pesticides. By the later years of the 20th century, productivity was declining and the cost of those inputs was becoming prohibitive on Inverary Downs.

Maintaining productivity while breaking the dependence on those inputs required an integrated approach to building soil organic matter comprising:

  • changing crop rotation practices to include cattle, green manure crops and longer fallow periods that gave time for soil micro-organisms to break down the green manure crops and crop residues

  • using compost-based fertilisers produced on the property from organic wastes obtained from places such as feedlots, chicken farms and stables

  • using cattle to break down stubble, which was previously burned, so that the organic matter is incorporated into the soil.
A penetrometer test shows deep, friable soil on Inveraray Downs

For further reading, we suggest the Soil organic matter- what does it mean for you? article published by the Grains Research & Development Corporation


How do you build soil organic matter on your property? We’d love to hear what you are doing to improve the soil organic matter in your part of Australia. You can let us know here or continue reading more inspiring stories from our other case studies in regenerative agriculture.

Intensive farming is eating up the Australian continent – but there’s another way

Tillage Radish and Clover

Intensive farming is eating up the Australian continent – but there’s another way

Sue McIntyre, Author provided

Last week we learned woody vegetation in New South Wales is being cleared at more than double the rate of the previous decade – and agriculture was responsible for more than half the destruction.

Farming now covers 58% of Australia, or 385 million hectares, and accounts for 59% of water extracted.

It’s painfully clear nature is buckling under the weight of farming’s demands. In the past decade, the federal government has listed ten ecological communities as endangered, or critically endangered, as a result of farming development and practices.

So how can we accommodate the needs of both farming and nature? Research shows us how – but it means accepting land as a finite resource, and operating within its limits. In doing so, farmers will also reap benefits.

Grassy eucalypt woodlands used for cattle farming in subtropical Queensland. Tara Martin. Author provided.

Healthy grazing landscapes

In the 1990s, I worked as a research ecologist in the cattle country of sub-tropical Queensland. The prevailing culture valued agricultural development over conservation. Yet many of these producers lived on viable farms that supported a wealth of native plants and animals.

They made a living from the native grassy eucalypt woodlands, an ecosystem that extends from Cape York to Tasmania. In these healthy landscapes, vigorous pastures of tall perennial grasses protected the soil, enriched it with carbon and fed the cattle.

Read more: IPCC’s land report shows the problem with farming based around oil, not soil

NSW and Victoria have similar eucalypt grassy vegetation, but farming here has taken a very different path.

Fertilised legumes and grasses grown for livestock fodder have replaced hundreds of native grassland plants. Over time, native trees and shrubs stopped regenerating and remaining trees became unhealthy, destroying wildlife habitat. The transformation was hastened by aerial applications of fertiliser and herbicide.

By 2006, 4.5 million hectares of box-gum grassy woodland – or 90% – in temperate Australia had been destroyed.

Aerial delivery of fertiliser, seed and herbicide transformed grassy woodlands in NSW. F. G. Swain. Author provided.

A template for sustainability

Back in Queensland in the 1990s, my colleagues and I devised a template for sustainable land use. Funded by the livestock industry and a now-defunct federal corporation, we worked with producers and government agencies to find the right balance between farm production and conserving natural resources.

Our research concluded that for farming to be sustainable, intensive land uses must be limited. Such intensive uses include crops and non-native pastures. They are “high input”, typically requiring fertilisers, herbicides and pesticides, and some form of cultivation. They return greater yields but kill native plants, and are prone to soil and nutrient runoff into waterways.

But our template was not adopted as conventional farming practice. In the past 20 years, Australia’s cropping area has increased by 18,200 square kilometres.

By 2019, 38,000 square kilometres of poplar box grassy woodland in Australia had been cleared – more than half the size of Tasmania. The ecosystem was listed as endangered in 2019. Until that point, it had been considered invasive native scrub in NSW – exempting it from clearing regulations – and was systematically cleared for agriculture in Queensland.

Farmers should conserve sufficient areas of landscape to support native plants and animals. Sue McIntyre, Author provided

Regenerating the land

Hearteningly, our research was recently revived in a multidisciplinary study of regenerative grazing on the grassy woodlands of NSW. The template was used to assess the ecological condition of participating farms.

The study examined differences in profitability between graziers who had adopted regenerative techniques such as low-input pasture management, and all other sheep, sheep-beef and mixed cropping-grazing farmers in their region.

Read more: Three ways farms of the future can feed the planet and heal it too

It found regenerative grazing was often more profitable than other types of farming, especially in dry years. Regenerative farmers also experienced significantly higher than average well-being compared with other NSW farmers.

So what does our template involve? First, it identifies four types of land use relevant to farmed grassy woodland regions.

Second, it specifies the proportion of land that should be allocated to each use, in order to achieve landscape health (see pie chart below). The proportions can be applied to single farm, or entire districts or regions.

How to sustain production, natural resources and native flora and fauna on a landscape or farm. Sue McIntyre

Intensive land use involves activities that replace nearly all native species. If these activities occupy more than 30% of the landscape, there’s insufficient habitat to maintain many native species, especially plants.

At least 10% of land must be devoted to nature conservation. The remaining 60% of the land should involve low-intensity activity such as grazed native pasture and timber production. If managed well, these land uses can support human livelihoods and a diversity of native species.

Within that split of land use, total native woodland should be no less than 30%. This guarantees connected habitats for native plants and animals, enabling movement and breeding opportunities.

Retaining grassy woodland ensures habitat for native animals. Duncan McCaskill/Flickr

Respect the land’s limits

Australians ask a lot of our land. It must make space for our houses, businesses, and roads. It should support all species to prevent extinctions. And it must produce our food and fibre.

Global population growth demands a rapid rise in food production. But relying on intensive agriculture to achieve this is unsustainable. Aside from damaging the land, it increases greenhouse gas emissions though mechanisation, fertilisation, chemical use and tree clearing.

Read more: Australian farmers are adapting to climate change

To meet the challenges of the future we must ensure farmed landscapes retain their ecological functions. In particular, maintaining biodiversity is key to climate adaptation. And as many of Australia’s plants and animals march towards extinction, the need to reverse biodiversity loss has never been greater.

Farmers can be profitable while maintaining and improving the ecological health of their land. It’s time to look harder at farming models that respect the limits of nature, and recognise that less can be more.

Sue McIntyre, Honorary Professor, Australian National University

To see farmed landscapes managed for biodiversity in action, look at our case studies.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Case study catch up: How is Milgadara performing in 2020?

Case study catch up: How is Milgadara performing in 2020?

Bill and Rhonda Daly were one of the first Soils For Life case studies in 2013. They are fourth generation farmers growing sheep, cattle and crops on their property Milgadara in Young, NSW, as well as running YLAD Living Soils – a composting business that allows them to enrich not just the soils on their property but many others across the whole country.

Watch the video to see the farm and hear Bill and Rhonda talk about their practices.

‘Courage, passion and never giving up’

When Soils For Life first profiled them in 2013, Bill and Rhonda told their story of change, outlining how they had started questioning conventional practices in the mid-1990s. Their search for alternatives led them to investigate biological, regenerative and biodynamic practices. After Rhonda was diagnosed with chronic meningitis and heavy mental poisoning in 2001 they knew they had to act. Twenty years on, they are reaping the benefits of shifting their mindset and adopting a regenerative, more mindful approach to their work.

“The resilience of our country has probably been the incredible thing that we’ve noticed since we’ve changed so many of our practices. It just bounces back so quickly after a big dry,” says Bill when Soils For Life caught up with the pair recently. They had managed to sow multi-species crops just before the rain in February and watched them grow to a meter high after the rain. “That’s what was really noticeable in this drought, it was really a lead-in drought of three years. And within four weeks after that rain, we had green. It’s just incredible.”

Resilient soils, resilient people

As the whole Daly family (Bill and Rhonda’s daughter, her partner and children all live on the farm) have sought to enrich the soils under their feet, they have also been enriched personally by the changes they have made on their farm. 

“I think resilience in soils and people is probably one of our greatest attributes – our past practices were able to give us the hope and the assurance that things were going to recover and come back again,” says Rhonda. And Bill agrees: “I know with the changes that we have made on the farm and in our own lives, that simplification of our system and the understanding of the way the countryside works, allows your mindset to be more relaxed in lots of respects. You’re not putting out fires all the time.”

Reaping the rewards

Recent ABARES data confirms that Bill and Rhonda’s biological, regenerative and biodynamic approach is a profitable one. Farming operations at Milgadara have been compared with other properties in the same region using ABARES data. This benchmarking process allows the business implications of management decisions to be compared using industry standard metrics. 

At $278/ha Milgadara produces 61% more profit per hectare than the region average of $173.  This is due to significantly higher income of $795/ha compared to $485/ha (Figure 1).

Milgadara income, expenses and profit compared to the region averages.
Figure 1 Milgadara income, expenses and profit compared to the region averages.

Wool production is a big contributor to profitability. Shearing occurs when the wool gets to 70mm, which is usually after around seven or eight months. Bill says that this actually makes the sheep operation a lot easier as they no longer have fly impacts, only drench on average once a year and often do not have to crutch sheep. Milgadara cut more than double the average amount of high quality wool per sheep with a corresponding increase in wool income (figure 2). Maintaining ground cover and feed budgeting is a big focus at Milgadara; “I made a very conscious decision to spell certain countries [rest certain areas] right from basically the beginning of the spring time last year. We didn’t have any stock on that right up until basically even into late April this year.” These paddocks were then used for this seasons lambing, giving other pastures a chance to recover.

A prime lamb operation remains part of the livestock system to maintain a strong cash flow. “It just makes that huge difference to how your yearly income is balanced rather than having to wait for one cheque a year,” says Bill. Cattle production is a trading operation with stock brought in when market and farm conditions are favourable. “I’d rather have the feed grow and allow it to make a healthy soil rather than lose money on cattle.”

Milgadara wool production and income compared to the region averages.
Figure 2 Milgadara wool production and income compared to the region averages.

With the Covid19 restrictions easing in NSW, Soils For Life will visit Milgadara in July to gain an understanding of how Bill and Rhonda’s practices are impacting the ecology and soil of the property. For more information on the Daly’s story of change, see our first case study here.

Water management in the land of droughts and flooding rains: Lessons from our case studies in low rainfall areas

Water management in the land of droughts and flooding rains: Lessons from our case studies in low rainfall areas

Managing grazing pressure, maintaining soil fertility, controlling weeds … the list of challenges facing agricultural land managers could go on and on. But, arguably the biggie, the black beast always lurking out there, is water. Sometimes there is too much of it, but that is rare in our land of droughts and flooding rains. Usually the problem is that there isn’t enough. Perhaps a solution in some circumstances is to focus on the flooding rains.

This article looks at the different approaches taken on our case study properties to manage big falls of rain when they come. It is evident from the range of approaches mentioned across all our case studies that there are creative ways to make the most of the available rainfall. The principle shared by each of the examples is an approach that slows the movement of water and allows it to seep into the soil. The ways and means vary depending on the land itself and resources available.

Water management: Scalds on Salisbury

Soils For Life’s Salisbury case study, about the MacAlpine family’s property in the north of central-western New South Wales  illustrates the problem, and the potential solution. Salisbury and several prior case studies provide lessons in water management that might be useful for many agricultural land managers.

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, probably less. The average and median monthly rainfall sometimes falls in a single day, sometimes causing regional flooding. Conversely, little or no rain falls for substantial periods. As if that doesn’t make life complicated enough, there are also the ‘scalds’ to deal with.

The early period of sheep grazing in the arid and semi-arid rangelands of western New South Wales was a disaster for topsoil. Overgrazing encouraged by high wool prices destroyed ground cover, which in dry periods led to widespread wind and water erosion that created ‘scalds’ where the coarser textured surface material has been completely lost, leaving the finer textured and less permeable subsoil [Figure 1]. This was reported as being an extensive problem as long ago as 1901 (Cunningham 1987). By the 1960s, tens of thousands of square kilometres of rangeland sites in western NSW were moderately bare or completely ‘scalded’ (Thompson 2008).

Water soaks into scalded land so slowly that soil moisture recharge, and the potential for revegetation, is negligible. The rare events of flooding rains do little more than cause more soil erosion. This land is perpetually barren, or would be without intervention.

water management on Salisbury
Figure 1: 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.

Methods for reclaiming scalded soils in Western NSW have been researched since the late 1940s (Cunningham 1987). Surveying and construction methods developed over several decades have made rehabilitation of scalds more and more cost-effective (Rhodes 1987). These 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).

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, recommence soil swelling and cracking and provide moisture down the soil profile. The banks and disturbance within the pond area 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 other wind-blown or sheep- or bird-delivered seed arrives, 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.

The results on Salisbury can be seen in Figure 2.

Pond bank and trenches
Figure 2: A horseshoe pond bank with water ponding in the trenches either side of the bank and across the surface. Regenerating vegetation is evident within the horseshoe.

Breaking the surface on Bokhara Plains

About 150 km north-west of Salisbury, on the Goodooga Road north of Brewarrina, is Bokhara Plains. In 1999 around 50% of the 7200 hectares property was clay pan or otherwise bare ground.Ponding had been tried on Bokhara Plains but, except at the edges of ponds where the soil had been disturbed, the effects were minimal. A cost-effective way to break up the hard capped surface to accelerate water penetration to capture the infrequent falls of rain was required.

The most cost-effective method found was to use cattle. The trick was, after a fall of rain when the surface was wet, to pack on a big enough mob of cattle so that the hooves could break the surface. However, because of the low carrying capacity on the property there weren’t sufficient numbers to do the job, so the landholders agisted cattle when the time was right to help break up the surface.

As well as Salisbury and Bokhara Plains, interventions to make the most of intermittent and unreliable rainfall have been implemented at Gilgunnia Station and Wyndham Station. Clay pans were not such a problem on these properties, further west in New South Wales, but the need to maximise the benefits of limited available rainfall is no less important. Rothesay, in the central west, illustrates the use of a similar technique in hillier country.

Water-spreading at Gilgunnia Station

Gilgunnia comprises 10,000 hectares on the Cobar Peneplain. Rainfall ranges from 101 mm in 1982 to 710 mm in 2010, and averages 398 mm. As is common in the region, rainfall comes in heavy falls. Here, the tendency is for it to run off the gravelly rises and through the flats without infiltrating and therefore exacerbating soil erosion. To add to the soil erosion hazard, turpentine bush and other invasive native shrub and tree species had taken over the original grassy woodland, considerably reducing grazing capacity. Removing that vegetation posed the risk of increasing soil erosion. Landscape engineering in the form of water-spreading banks was implemented to help address these issues.

Water spreading is suited to broad flats between 100 metres and 1 kilometre wide. The system at Gilgunnia comprises concentric curved banks constructed along the contour, spaced a few hundred metres apart (Figure 3). The banks prevent runoff from accumulating down drainage lines, and therefore stabilise erosion, and increase water infiltration. A gap is left in the bank at alternating points along the length of each bank. Runoff ponds behind the banks and infiltrates through the gaps, making its way to and fro gradually down through the broad flats. Organic matter accumulates behind the banks, trapping seeds and accelerating revegetation.

Shallow contour banks
Figure 3: Shallow contour banks on Gilgunnia [Photo: Google maps]

Improving water distribution on Wyndham Station, Rothesay and Balala

Wyndham Station on the lower Darling River is even further west in New South Wales – in fact it’s not much further to get to South Australia. The average annual rainfall here is only 260 mm. Rothesay is in central NSW at the foothills of the Liverpool Plains, where the average annual rainfall is a rather more generous 691 mm. But the same problem arises: there are good years, and there are drought years.

The topography on Gilgunnia and at Rothesay is more pronounced than at Gilgunnia or Salisbury, so different solutions apply. Low banks and channels are constructed at a shallow down-grade from drainage lines towards the ridges. Runoff follows the channels and disperses down the slopes.

Fallen trees strategically placed to catch organic matter and slow wate
Figure 4: Balala Station; fallen trees strategically placed to catch organic matter and slow water flow down the slope.

A different approach has been taken at Balala, west of Uralla in northern New South Wales. Following a long history of set stocking, woody native vegetation over substantial parts of Balala had become substantially denser than the original grassy woodland, to the extent that the grasses were suppressed and there was little grazing potential. Approval was obtained to thin some areas of overly dense stands. That helped pasture rejuvenation but created the problem that there was woody debris to deal with. Turning that problem into an asset, piles of stems and branches were laid along the contour on gentle slopes (Figure 4). The effect of the piles was to impede surface water flow, which increases infiltration, and to trap organic matter. As well as making better use of available rainfall, research has found that this method improves soil nitrogen and carbon content and nutrient exchange properties (Tongway and Ludwig 2006).

Bundles of woody debris or “Brush Packs” were installed in the Mulloon Creek catchment as part of the Green Army program. The Mulloon Institute produced a guide to the use of “Brush Packs” following the bushfires of 2019/20. Retaining organic matter and nutrients after fires increases the speed of landscape recovery and protects water systems.

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.

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

Tongway, D. and Ludwig, J. 2006. Rehabilitation of Semiarid Landscapes in Australia. I. Restoring Productive Soil Patches. Restoration Ecology. 4. 388–397. 10.1111/j.1526-100X.1996.tb00191.x.

Birds: Why and how to measure them on your property

Birds: Why and how to measure them on your property

By Richard Thackway and Greg Hosking

Results of repeated bird surveys, like repeated soil tests, can provide land managers with valuable information on how their land management is performing over time. In fact, the number and different types of birds​ found in different types of vegetation on a property can be used​ as a​ measure of​ management performance.   

Why measure birds in your landscape

Birds are a practical indicator to monitor biodiversity. Any changes that you make to vegetation on your property will influence the type and number of birds by changing the availability of food, habitat or shelter. ​For instance, you might choose to remove​ exotic weed species and replace these with​ locally indigenous native plant species. ​Or you could decide to fence and revegetate an area of your property. Both management practices are likely to see some kind of change in food, habitat and shelter for birds. 

Before​ you change the management of an area, it’s a good idea to establish a repeatable way to measure bird life. By establishing a robust survey, then repeating it in the same season each year over following years, you will measure the impact on biodiversity that the changes your management practices have on the landscape.

Birds and vegetation

You can expect​ that​ establishing native plant shelterbelts or fencing out remnant patches of native vegetation will provide more​ habitat for local bird species to occupy.​ As a patch of vegetation matures (i.e. becomes more vertically complex and provides more resources like food, shelter and nest sites) it’s usual for a greater number and variety of​​ birds to be present. However, one factor that strongly influences the variety and number of birds found in such sites is how well the native vegetation on the property is connected with larger patches of mature native vegetation in the surrounding landscape. 

Garry Kadwell’s property ‘Fairhalt’, a Soils For Life case study, illustrates how this works in practice. His well-considered approach to the size, connectivity and proximity of his revegetation projects increased the numbers and types of birds visiting and staying to breed.

Revegetating a site with native plant​ species and​ encouraging​ the regeneration of native​ tree, shrub and ground cover plants will influence the types of birds and the number of birds over time and in different seasons. However, established non-natives also provide valuable habitat for birds so it’s important to consider their value to bird life and the other roles they play in the landscape (ie shade, amenity, stabilising waterways) before removing them.

Measuring bird life over time

Consistently recording the bird communities found on your property can provide you with valuable information about how the quality and extent of bird habitat has changed over time. We encourage land managers to use the same bird survey technique each time that they survey birds. 

To limit the variables, make sure you repeat your survey in the same season every year. An ideal time to survey birds is the first week of ‘spring’ (whatever time that may be in your agro-climatic region). For example, in Canberra it’s best to survey in the first week of October. Whatever time of the year you choose make sure you perform the survey at that same time in following years. Of course, you may wish to survey multiple times each year, depending on the seasonal variation of your climate. In rangelands settings, it is best to do this survey up to three weeks after rain.

Doing your first survey BEFORE you make changes (e.g. removing​ the weeds​ or fencing a remnant patch of native vegetation) will give you a fuller understanding of the impact of the changes on the landscape. 

The Soils For Life Bird Survey

To assist you to conduct robust and repeatable bird surveys, we have produced an easy to use bird survey template. Filling it out over seasons will provide more detailed and useful information about the bird life on your property than a simple species list. You may need multiple copies if you have a lot of bird life on your property.

Other survey techniques

Birdlife Australia has information on other types of bird survey techniques available for use on farms. They have also developed an app for mobile devices which can be used to record bird surveys. The Birddata app is free to download/use for both Android and Apple users. A range of different survey methods are available to use within the app. It also gives you the opportunity to trial different survey methods to determine the method that best suits your purposes, once you’ve found what works sticking to that method is the recommended approach. 

Talaheni ridge line showing two types of vegetation cover.

Things to consider when conducting a survey

  • Survey at the same time of year every year. The first week of spring each year is a good time.
  • Use the same survey technique each time you survey. 
  • Set a duration of time that you will spend on the survey (ie one hour) and use that duration consistently each time you complete a survey.
  • Different types of vegetation-cover and land use deserve a separate survey. For example, do separate surveys for ridges, slopes, river flats, dams etc. 
  • Use binoculars. They don’t need to be expensive, but 8 or 10 x 42 are best for birdwatching.
  • Pleasant weather – without wind and rain – is best for bird watching.

How to identify bird species

Many of you will have a field guide on your bookshelf or kitchen bench. You can use this to help you identify the species of bird. If you don’t already have one, the commonly used bird identification manuals across Australia are:

For more information on identifying bird species try the following places:

Want to know how to improve bird life on your property? Jillamatong, Fairhalt and Talaheni are Soils For Life case studies that have all reported positive change in bird life over time.

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.

What is a Weed?

by Greg Hosking & Richard Thackway

Weeds are one of the major problems affecting Australia’s natural ecosystems and agricultural vegetation. Weeds have major impacts on the health, safety, amenity, economic well-being and quality of life of Australians (McNaught et al. 2006). However, deciding what is and isn’t a weed is complicated but important. Statements such as “all plants are good” or “all non-native plants are weeds” are inflexible statements and do not encourage viewing the environment in question as a system made up of numerous functioning parts.

The Cambridge Dictionary definition of a “weed” is any plant that is considered to be undesirable in a particular location (Dictionary 2016). It is a rather loose definition; it is open for personal interpretation. For example, the blackberry (Rubus fruticosus agg.) was brought to Australia from Britain in the 1840’s, it was introduced for its fruit and suitability for growing into hedges (DPIE 2020). Shortly after introduction, the plant spread widely throughout the south-east of Australia choking up waterways and pastures and by the 1880’s many people considered it to be a weed (DPEI 2020). However, some people look for the positive effects that weeds can provide in an environment. In landscapes that have been highly modified for agricultural production Blackberry bushes provide habitat for smaller bird species such as the superb fairywren (Malurus cyaneus) (Nias 1984). Whilst providing habitat for a few species of birds is important, the value of this service must be considered alongside the negative impacts weeds can have on the environment.

Some plants are labelled as “weedy” because of their ability to outcompete other plants, invade and colonise disturbed land and create monocultures. Monocultures caused by invasive species can have detrimental effects on local wildlife, reducing their habitat and food supplies (Ferdinands et al. 1984). A characteristic of many weeds is their ability to more successfully occupy some locations where native plants once thrived, thus pushing native plants to the fringes. For some species this results in localised extinction and in extreme cases can result in total species extinction (Groves & Willis 1999). In some agricultural landscapes some weed incursions have proven so extreme that agricultural production is forced to stop completely. The prickly pear invasion of the 1930s in central Queensland is a case in point.

Currently in Australia some plants are considered to be noxious weeds and various state governments legally require that landholders must undertake methods to control noxious weeds, failure to do so can result in fines. African lovegrass (Eragrostis curvula) and serrated tussock (Nassella trichotoma) are two examples of plants which must be controlled within the state of New South Wales (NSW DPI 2019). African lovegrass and serrated tussock are known for their ability to outcompete other grass species, native and non-natives alike, they are both largely unpalatable with little nutritional value for livestock or native animals (NSW DPI 2019). Strong cases have been made for actively controlling and removing African lovegrass (Curhes et al. 2009) and serrated tussock (Sinden et al. 2004).

African Lovegrass (Eragrostis curvula)
Close up of Tussock grass (Eragrostis curvula) in messy formation on dry ground

There are, however, those who advocate for the value of weeds: permaculturists use the term “naturalised” rather than “invasive” species. This term change within the permaculture movement stems from the consideration that all plants can be useful and provide a function to the environment (Holmgren 2011). Their argument is that naturalised species fill an important function/s which was previously lacking from the environment. An example of a weed which provides an ecological function is galvanised burr (Sclerolaena birchii). It is native to the rangelands of Australia and appears typically after periods of drought and is found in areas that have been highly disturbed e.g. overgrazed by livestock. Galvanised burr acts as a scab, covering bare ground and aiding soil health in repairing after periods of high stress (Auld 1981). As such, invasive plants like galvanised burr can be used an indicator of land condition.

Galvanised burr (Sclerolaena birchii) provides ecological function

Within the regenerative agriculture movement there is no uniform idea or opinion of weeds. Some land managers subscribe to the theory that every plant has a function and should be promoted whilst others recognise the damage particular plant species can cause. Some regenerative land managers in grazing landscapes have shown that their understanding of the vulnerabilities of weed ecology and biology can be used to control and remove weeds. For example, promoting the succession of pasture species through paddock rotations involving intensive short grazing periods combined with long recovery times without any grazing can result in weeds being outcompeted by desired pasture species.   

The term “weed” means many different things to many different people. When assessing if a plant is a “weed” it is worth considering that some plants that are considered weeds can provide valuable ecological functions at different times and in certain circumstances. Conversely, plant species which dominate an ecosystem and cause extinction of other species through the creation of monocultures should not be encouraged, either inadvertently or deliberately. Use of the term “weed” should be used advisedly and should involve consideration of the likely positive and negative effects that a plant species has on the landscape.

References:

Auld, B.A. (1981). Aspects of the population ecology of Galvanised Burr (Sclerolaena birchii). The Rangeland Journal, 3(2), pp.142-148.

Curhes, S. Leigh, C. and Walton, C. (2009). Weed risk assessment: African lovegrass Eragrostis curvula.

Department of Planning, Industry and Environment. (2020). Blackberry. [online] Available at: https://www.environment.nsw.gov.au/topics/animals-and-plants/pest-animals-and-weeds/weeds/widespread-weeds/exotic-vines/blackberry [Accessed 7 March 2020].

Dictionary, o. (2016). weed Meaning in the Cambridge English Dictionary. [online] Dictionary.cambridge.org. Available at: http://dictionary.cambridge.org/dictionary/english/weed [Accessed 7 March 2020].

Ferdinands, K., Beggs, K. and Whitehead, P. (2005). Biodiversity and invasive grass species: multiple-use or monoculture?. Wildlife Research32(5), pp.447-457.

Groves, R.H. and Willis, A.J. (1999). Environmental weeds and loss of native plant biodiversity: some Australian examples. Australian Journal of Environmental Management, 6(3), pp.164-171.

Holmgren, D. (2011). Weeds or wild nature: a permaculture perspective. Plant Protection Quarterly, 26(3), p.92.

McNaught, I., Thackway, R., Brown, L., and Parsons, M. (2006). A field manual for surveying and mapping nationally significant weeds. Bureau of Rural Sciences, Canberra.

Nias, R. C. (1984). Territory quality and group size in the superb fairy-wren Malurus cyaneus. Emu 84: 178-180.

NSW Department of Primary Industries. (2019). African lovegrass (Eragrostis curvula) [online]. Available at: https://weeds.dpi.nsw.gov.au/Weeds/Details/3 [Accessed 7 March 2020].

NSW Department of Primary Industries. (2019). Serrated tussock (Nassella trichotoma) [online]. Available at: https://weeds.dpi.nsw.gov.au/Weeds/Details/123 [Accessed 7 March 2020].

Sinden, J. Jones, R. Hester, S. Odom, D. Kalisch, C. James, R. Cacho, O. and Griffith, G. (2004). The economic impact of weeds in Australia. Technical Series, 8.