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:
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.
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.
Katherine 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.
The global ‘just-in-time’ industrial food and supermarket system is not fit for purpose in guaranteeing food security.
As the world reels under corona virus and the resulting
economic meltdown, another crisis – far
more serious – appears to be building: the potential collapse of global food
supply chains.
For those who cry “We don’t want any more bad news”, the
fact of the matter is we have landed in our present mess – climate, disease,
extinction, pollution, WMD – because we steadfastly ignored previous warnings.
The first warning of a corona pandemic was issued in a
scientific paper in 2007 and was blithely ignored for thirteen years. In it,
the scientists explicitly stated “The presence of a large reservoir of
SARS-CoV-like viruses in horseshoe bats, together with the culture of eating
exotic mammals in southern China, is a time bomb. The possibility of the re-emergence
of SARS and other novel viruses from animals or laboratories and therefore the
need for preparedness should not be ignored.” [i]
Similarly, in 1979, the World Meteorological Organisation
warned “… the probability of a man-induced future global warming is much
greater and increases with time. Soon after the turn of the century a level may
possibly be reached that is exceeds all warm periods of the last 1000-2000
years.” [ii]
And climate warnings have been coming thick and fast ever since, to scant
avail.
Now we have a new warning from the UN Food and Agriculture
Organisation, a cautious body if ever there was one, that states “We risk a
looming food crisis unless measures are taken fast to protect the most
vulnerable, keep global food supply chains alive and mitigate the pandemic’s
impacts across the food system.” [iii]
Border closures, quarantines and market, supply chain and
trade disruptions are listed as the chief reasons for concern. However, like
many national governments, FAO insists “there is no need to panic” as world food
production remains ample.
This, however, depends on fragile assumptions. It assumes
that farmers and their families do not get sick. It assumes they will always be
able to access the fuel, fertiliser, seed and other inputs they need when
supply chains disintegrate. It assumes the truck drivers who transport food to
the cities do not get sick, that markets, cool stores and food processing
plants are not closed to protect their workers. That supermarkets continue to
function, even when their shelves are stripped bare. All of which is starting
to appear tenuous.
There is never a ‘need to panic’ as it does not help in
resolving difficult situations. But there is definitely a need to take well-planned
precautions – as we have failed to do in the cases of climate and corona virus.
The looming food crisis starts from three primary causes:
The global ‘just-in-time’ industrial food and
supermarket system is not fit for purpose in guaranteeing food security. It is
all about money, and not about human safety or nutrition. Its links are fragile
and any of them can break, precipitating chaos – especially in big cities.
The agricultural system we know and love is
becoming increasingly unreliable owing to climate change, catastrophic loss of
soils worldwide, shortages of water and narrowing of its genetic base. Farmers
are struggling with their own pandemics in the form of swine fever, army worms
and locusts. This unreliability will become increasingly critical from the
2020s to the mid-century.
The predatory world economic system now punishes
farmers by paying them less and less for their produce, driving them off their
farms and increasingly forcing those who remain to use unsustainable methods of
food production. This is causing a worldwide loss of farmers and their skills
and destruction of the agricultural resource base and ecosystem at a time of rising
food instability.[iv]
The reason that a food crisis is far more serious than
either the corona virus or its economic meltdown, is that the death toll is
generally far larger. More than 200 million people have died in various famines
over the last century and a half, and many of those famines led to civil wars,
international wars and governmental collapses. That is why we need to pay
attention now – before a new global food crisis arises. Not brush it aside, as
so many inept world leaders have done with the virus.
The Spanish have a well-learned saying that “Lo que separa
la civilización de la anarquía son solo siete comidas.” [v]
The French and Russian Revolutions both arose out of famines. WWII arose partly
out of Hitler’s desire to capture Soviet farmlands in order to avoid another
WW1 famine in Germany. Many modern African wars are over food or the means to
produce it. The Syrian civil war began with a climate-driven food crisis.
Indeed, there is growing evidence that lack of food plays a catalytic role in
around two thirds of contemporary armed conflicts. As US former president Jimmy
Carter has observed “Hungry people are not peaceful people.” [vi]
Food failures bring down governments and cause states to
fail. In 2012 a drought in Russia and the Ukraine forced them to cut grain
supplies to Egypt and Libya – where governments promptly fell to popular
revolutions. It was a strange echo of history: in the third century a
combination of climate change and a pandemic caused a failure in grain supplies
from North Africa, an economic crash and, ultimately, the end of the Roman
Empire.
While there is ‘no need to panic’ over food, there is a very
clear and urgent need for plans to forestall major shortages around the world. Yet,
there is very little evidence that governments worldwide are preparing to head
off a food crisis, other than to reassure their citizens, Trumplike, that there
isn’t a problem. However, lack of trust
by citizens in their governments has already prompted a global rush to stock up
on staple foods which has ‘upended’ the vulnerable ‘just-in-time’ food delivery
system in many countries.[vii]
Over four billion people now inhabit the world’s great
cities – and not one of those cities can feed itself. Not even close. None of
them are prepared for catastrophic failure in fragile modern food chains, on
which they are totally reliant. It would appear almost nobody has even dreamed
of such a thing. We are sleepwalking into something far larger and far more
deadly than corona virus. The delicate web of modern civilization is fraying.
What is to be done? The short answers are:
Introduce emergency urban food stocks
Compulsory reduction of food waste at all points
Prepare for WWII-style rationing if needed
Pay farmers a fair return
Increase school meals programs and food aid to
the poor
Encourage local food production and urban food
gardens
Develop a global emergency food aid network as a
priority
Reinvent food on a three-tier global model
encompassing: regenerative farming, urban food production (and recycling),
accelerated deep ocean aquaculture and algae culture.
There are few crises that cannot be avoided with careful
forward planning, including the ten catastrophic risks now facing humanity as a
whole. [viii]
It is time we, as a species, learned to think ahead better
than we do, and not listen to those who cry “no more bad news, please”. They
only lead us into further crisis.
*Julian Cribb is an Australian science author. His book Food or War describes what must be done to secure the world’s food supply.
REFERENCES
[i]
Cheung VCC et al., Severe Acute Respiratory Syndrome Coronavirus as an Agent of
Emerging and Reemerging Infection. Clinical Microbiology Reviews Oct 2007, 20
(4) 660-694; DOI: 10.1128/CMR.00023-07
[iv]
These issues are extensively analysed in my recent book Food or War,
Cambridge University Press, 2019. https://www.cambridge.org/us/academic/food-or-war
[v]
Civilization and anarchy are only seven meals apart.
[vi]
Carter J., First Step to Peace is Eradicating Hunger. International Herald
Tribune, June 17, 1999.
[vii]
Lee A, How the UK’s just-in-time delivery model crumbled under coronavirus.
Wired, 30 March 2020.
An ecological report is produced for each case study in the Soils for Life program. To produce an ecological report the Soils for Life team follows a robust formula developed and tested by Richard Thackway, Honorary Associate Professor at The Australian National University and long-term member of the Soils for Life team.
Land managers typically keep production and financial records over time and have no written record of the regenerative management of their farm and outcomes of regenerative practices applied to their farm. Soils For Life ecological assessors use a handbook for preparing ecological reports. An assessment on “Pallerang”, a farm in the Mulloon Creek Catchment, is an example of the approach detailed in the handbook.
The ecological report quantifies what has happened ecologically on a
farm over decades. A detailed ecological report consists of 20 to 30
pages.
The Soils for Life ecological assessor supports the land holder to develop a chronology of the production systems for the main land types their land. Production systems include time based paddock grazing, no-till cropping, minimum use and biodiversity protection, revegetation, controlling wildfire, controlling feral animals and weeds, and fencing water points and creek to exclude stock. The ecological assessor can liaise with the farmer remotely via telephone and email.
The land holder completes a graphic response to ten ecological assessment criteria which is the land holder’s interpretation of what has occurred ecologically on the property during their management.
The land manager provides reports, photographs and results of soil tests, and water and biodiversity surveys.
The chronology of production systems and the farmer’s graphic responses indicate the impacts of the land holder’s management decisions on the ecological health of the land.
Satellite imagery verifies the ecological transformation and health
of the agricultural landscape. Ground cover and actively
photosynthesising vegetation
are analysed using satellite imagery. Ground cover on the property
is compared to the surrounding district which provides an independent
verification
of the regenerative capacity of the land.
A three to five-page summary ecological report is produced by the
Soils for Life team and included in the case study, promoted on the
website and on the
social media platforms.
Greg Hosking is an ecologist. Honorary Associate Professor Richard Thackway is a Research Scientist. Both Greg and Richard are members of the Soils for Life team.
Building bridges between stakeholders with different perspectives helps to advance regenerative agriculture practice. One way of addressing contested issues is to provide opportunities to share and respect different opinions and understandings.
A lively discussion in the Soils for Life Facebook Group followed the publication of Prof. White’s article. We welcome all thoughtful comments; we’ve attempted to do them justice selecting two constructive threads from the comments.
Diverse communities
A homogenous group of soil scientists does not exist. Several readers
referred to Nicole Masters and Christine Jones as two soil scientists
who identify
as both soil scientists and as regenerative agriculturalists. There
are many examples where soil scientists participate in mainstream
academia and
collaborate with farmers who are implementing regenerative
principles such as integrating crops and livestock, increasing
biodiversity, and enriching
soil carbon. Soils For Life is a member of the Soils CRC (Cooperative Research Centre), a program supporting
such collaborations.
One major project within the Soils CRC is a collaboration between scientists and a group of ten
leading regenerative farmers to design and implement a research project.
We’re looking forward to sharing the results of this innovative project.
Do these examples negate the “clash”? Probably not. They are helping to share knowledge and build a universal understanding.
The community of regenerative agriculturalists is equally as diverse as that of the soil scientists. There is no one view on whether it is necessary, or even appropriate, to use scientific data to prove the benefits of regenerative agriculture. On the one hand, those with a holistic emphasis on the physical, spiritual, and emotional elements of regenerative agriculture argue that reductionist approaches to science are unable to account for the systems perspective and do justice to the self- organising complex adaptive system. We may not yet have the tools to account for more holistic perspectives and the ecological basis of many regenerative practices. On the other hand, there are those who need proof to influence policymakers, neighbouring farmers, investors, and consumers. Both perspectives are valued and valid.
Soil formation
One thread of the discussion concerns the rate of soil formation. The
comments in the Facebook discussion group illustrate how semantics can
fuel the disconnect
between soil scientists and regenerative agriculturalists. In this
example, ‘soil formation’ is interpreted in two distinct ways and
results in discord
between some soil scientists and regenerative agriculturalists.
When referring to ‘regenerating topsoil,’ the rate of soil formation is orders of magnitude greater than if you are referring to ‘rock weathering into soil minerals.’ Identifying such distinctions can reduce conflict.
Building bridges
With a common focus on the role of carbon and soil biota in healthy
soils, the overlap between the diverse soil science and regenerative
agriculture communities
is increasing. A variety of perspectives, be they grounded in
science or lived experience, are useful when it comes to regenerating
land. Respectful
communication amongst all those with a stake in the future of our
food and farming systems will enable progress in the quest for healthy
soils, food,
water and animals.
The Soils for Life comms team thanks all participants for your contribution to the Facebook discussion group. We encourage all stakeholders to stay engaged.
Biodiversity is a term used to refer to the amount of living organisms found in any given area. Higher numbers of living organisms (types of species and their abundances) i.e., biodiversity, indicate a healthier landscape. Due to the nature of most living organisms, it can be challenging to measure their abundance.
However, unlike most other living organisms, bird species richness (different types of species) and abundance can be observed and measured by most people with some small degree of skill. Different birds occupy different habitats in different seasons and different times of the diurnal cycle. Birds are typically easy to observe with a pair of binoculars and a field guide to the local bird species. Birdwatchers with a high degree of skill or “Twitchers” are often able to identify and count birds by their calls.
Birds are a practical indicator of biodiversity
In healthy landscapes, seed eater, foliage grazer, insectivore, nectivore, omnivore, and carnivore birds can represent the full range of trophic levels. Changes in land use and management affect shelter, food, and habitat resources available to birds. Collectively, these characteristics make birds an excellent practical indicator to monitor and report the health of biodiversity on the property.
Suberp Fairy Wren. Photo: Belinda Wilson
Biodiversity plays a vital role in helping decision-makers to understand the ecological function, structure, and composition of ecosystems of land use types, including regenerative agriculture. Regenerative land managers often use birds as an indicator of ecosystem condition to assess the effects of land management practices on agricultural landscapes. Being able to observe changes in biodiversity, before and after adopting regenerative land management practices, can provide land managers with support and validation of whether what they are doing is working.
Bird surveys
The Marsh family are leading figures in Australian regenerative agriculture. Since 2000 the family has supported ongoing bird surveys on their property near Boorowa NSW. Researchers from Greening Australia conducted the studies. Richard Thackway compiled and analysed the data. In 1980 3% (20.6 ha) of the Marsh’s property was covered by native vegetation trees and shrubs. In 2012 that coverage had increased to 20% (82.4 ha) of the property. The progressive increases in the extent of trees and shrubs occurred because of the Marsh’s investment in revegetation on the property.
Greening Australia conducted the bird surveys at three sites, two located within revegetated areas and one location in a grazing paddock without revegetation. In 2000 an average of 7 species of birds were observed in the revegetated places, and by 2017 this number had increased to 19 (Figure 1).
Figure 1. Extent of trees and shrubs compared to the numbers of bird species (Richard Thackway).
The increase in bird species observed on the Marsh’s property coincided with the expansion and development of the revegetated areas. As the revegetation aged, these areas provided resources for different bird species, including; shelter, habitat, nest sites, and food. If these resources are not present in the landscape, selected species will not occur in an area, for example, the Superb Fairy Wren (Malurus cyaneus) requires a habitat of dense cover and low shrubs.
Birds at Illawong
Bryan Ward is a Soils for Life case-study land manager. Bryan utilises birds as an indicator of biodiversity and landscape health. Investing in direct-drill seeding of native plant trees and shrubs species across much of his property resulted in improved habitat and resources for birds on his farm near Albury, NSW. Local ecologist Ian Davidson conducted a survey of birds in 2018. Ian found that the number of bird species on Illawong greatly exceeded the numbers found on nearby properties. Neighbouring farms had not invested in revegetation activities.
The improvements in biodiversity observed on the Marsh and Ward properties are the results of their regenerative landscape management activities in an agricultural setting. By improving the extent and condition of native vegetation, both land managers improved the health of their landscapes.
Both the Marsh family and Bryan Ward manage their rural properties primarily for beef cattle production and have gained significant personal satisfaction by improving the biodiversity on their farms. Land managers who enable and promote enhancements in biodiversity receive multiple benefits. Enabling researchers to conduct standardised bird surveys in space and time, on their properties can lead to a sense of achievement for land managers. The aesthetics of a visually appealing landscape are a boon to farm managers and visitors alike. Farming families can enjoy the seasonal and annual cycles that result from enhancing the local biodiversity. Biodiversity brings improved social health and wellbeing; and contributes to the health of the local and regional landscapes.
Greg Hosking is an ecologist. Honorary Associate Professor Richard Thackway is a Research Scientist. Both Greg and Richard are members of the Soils for Life team.
In recent months regenerative agriculture has come into the public focus, the Prime Minister appointed a National Soils Advocate and and leading media organisations are regularly publishing articles about regenerative agriculture. Much of the eastern half of Australia is experiencing severe drought conditions. Regenerative agriculture could be the answer to Australia’s drought problem. Practitioners of regenerative agriculture improve the quality of their soil through various methods, which can result in improved water holding capacity within soil. Improving the water holding capacity of soil ensures that moisture is available for plants to utilise long after rainfall. Retaining soil moisture is one way to limit the effect of prolonged drought periods.
Landholders are now asking the question:
How do I make my property regenerative?
This article outlines three steps.
Step 1
The first step to becoming regenerative is to understand the different aspects of a property and how the management practices of the property affect the landscape. Points of interest are soil type, vegetation type, water supply, and topography. Understanding how management practices affect the different aspects of a property is a critical component in becoming regenerative. A cattle grazier in the Albury area would implement management steps to become regenerative. A sugarcane farmer from Murwillumbah would take different actions. A land manager who understands the relationship between their management practices and the landscape is prepared and ready to implement strategic changes on their property. An example of this is Soils for Life case study farm, Future Farming Landscapes (FFL) Winlaton. FFL Winlaton purchased land in the Swan Hill region of Victoria and set about understanding the different aspects of the landscape before they transitioned to a regenerative management system.
Step 2
The second step is to seek knowledge from regenerative land managers. The best advice is available from those farmers who operate a similar enterprise in the same landscape. Soils for Life has published numerous case studies about regenerative land managers throughout Australia. Further advice is available from regenerative agriculture consultants in diverse regional areas. The information and knowledge gained from communicating with regenerative land managers and consultants can be used to decide what strategic changes to make to the management practices of the property. Developing a plan which outlines the changes and the desired impact of those changes will provide a clear goal in the process of becoming regenerative.
Step 3
The third step is to stick to the plan. Set small manageable goals
that can be achieved. Small goals are stepping stones on the path to
becoming regenerative.
Achieving small goals encourage us to continue and help to increase
the resilience of the enterprise. Robert Quirk from Stotts Creek NSW is a
Soils
for Life case study farmer. The Stotts Creek case study is due to be
published in the next few weeks. Robert provides an example of a land
manager
setting small goals to achieve the overarching goal of improving
landscape function and health on his property.
Following these three steps won’t guarantee that a property will
become regenerative. However, it will help the land manager to
understand the impact that
their management decisions have on the landscape they operate
within.
Article by Greg Hosking. Greg Hosking is a member of the Soils
for Life team. Greg is an ecologist with an interest in understanding
how and why agricultural landscapes change over time.
A Future Directions International interview by Geoffrey Craggs, Research Analyst, Northern Australia and Regional Development
The National Soils Advocate:
“As the Soils Advocate, I have been tasked by the Prime Minister to increase awareness of and advocate the critical importance of conserving and improving agricultural soil and landscape conditions to: benefit the environment; enhance agricultural productivity and realise continuing economic benefits; and secure sustainable food production systems.”
Key points:
The National Soils Advocate role is to progress the national objective to protect, restore and maintain the health of the Australian agricultural landscape in order to guarantee food security and sustainable farming communities.
The role requires wide engagement and communication with Federal and State Governments, the scientific, research and technical communities, land managers and farmers as well as the broader Australian community at all levels.
Scientific research and development, followed by education and training for farmers, land managers and food producers will be key to future food security.
Research conducted and published by independent and not-for-profit organisations will be important to enabling wide understanding issues.
A number of recently published Soils For Life case studies demonstrate that revegetation activities have on-farm production and environmental benefits, ranging from animal productivity improvements to soil protection and provision of ecological habitat.
Approaching revegetation activities can be as diverse as the trees and shrubs being planted. Here’s a snapshot of some of the production, soil and ecological benefits trees provide.
Production benefits
Revegetation comes with costs, so a logical question is what are the benefits to the farm business.
Trees provide shelter for livestock, pasture and crops. One study in
Australia estimated that tree plantings in the form of shelterbelts can
reduce windspeeds
by up to 50% with significant benefits to pasture, livestock and
crop production. Livestock farmers, Martin Royds (Jillamatong)
and Bryan Ward (Illawong),
two of Soils For Life’s recent case study farmers, both attribute
increased animal
comfort to their tree plantings. On both these properties,
revegetation has been an important element of their regenerative
management practices. More
research on the relationship between grazing animal productivity and
tree shelter would be beneficial to support this type of regenerative
management.
Trees also provide additional income streams on farms. For example, on another of our recent case studies, Brownlow Hill on the Cumberland Plain in NSW, Edgar and Lynne Downes manage 225 ha of Forest Red Gum Grassy Woodland under the NSW Government’s biobanking scheme. Under this scheme, they are paid to maintain the integrity of the vegetation. The Future Farming Landscapes at Winlaton participates in a similar program in Victoria (the Bush Tender Program).
Soil health benefits
From physical protection of soil to improving soil fertility, trees are as much an asset to the soil as soils are to trees.
One of the most commonly understood advantages of revegetation on
farms is soil erosion control. For example, on Illawong, Bryan Ward
planted trees above
and inside existing erosion gullies and on bare rocky ridges. These
plantings have stabilised the soil, slowed down the water flow and
improved soil
water infiltration on his property. The water quality on his dams is
one clear indicator that he has erosion under control.
On Jillamatong, Martin Royds’s paddock layout works in concert with the tree plantings to provide soil fertility benefits. The fence lines run upslope to the more elevated country, where many of the trees are planted. With this paddock layout, the shelter provided by the trees lures the cattle up to the tops of slopes enabling the livestock to transfer nutrients, in the form of manure, from the more fertile flats to the upper slopes of the farm. The improved nutrient status of soils on the upper slopes of the farm impacts pasture quality and productivity.
Ecological benefits
Providing habitat for native fauna is a key ecological function of
trees on farms. And, besides the conservation value, enhanced
biodiversity has the added
value of natural pest control.
On Illawong, one of Bryan Ward’s revegetation strategies involved
fencing off remnant paddock trees and direct seeding native vegetation
around the trees.
He has effectively reversed scattered tree decline on his property
and created tree patches with diverse structure and composition. These
patches have
led to a resurgance of native fauna on his property. A bird survey
in 2018 reported 53 bird species over a 30 minute observation period.
This confirms
that the trees on Illawong provide critical habitat, shelter and
food for native fauna.
On Jillamatong, Martin Royds has used lanes of trees to connect
neighbouring forested hills and made efforts to ensure tree plantings
include understorey
species. A focus on connectivity and also an emphasis on vegetation
structure has enhanced the habitat value of the trees on his property.
The examples drawn from the recent Soils For Life case studies that
are described here, while not an exhaustive list of what’s possible with
trees, do
demonstrate two clear points:
1.Reasons and approaches to revegetation depend on context and management objectives.
2.Revegetation, when part of a holistic management approach, provides
production, soil health and ecological benefits that cannot be
separated from each
other.
Any animal that is eating grass when it is trying to grow immediately after rain is reducing the flow of carbon into the paddock. This results in reduced ground cover and lowers potential production. If the grazing pressure is excessive it can reduce paddock health. This is why removing sheep and cattle from pastures whenever possible after rain is a good idea, but kangaroos are an animal that we can’t manage when they are present.
Photo 1: The outcome of restricting kangaroos to a sensible population (October 2018)
Kangaroos have the ability to get through normal fences, so can turn up in mass after storms and consume new growth, sometimes the lot if pastures are very low.
Kangaroos do the most damage to the environment during extended dry periods when perennial grasses are forced to go into dormancy more often. To come out of dormancy after any rain that falls, they call on stored energy reserves. If perennial grasses are continually not allowed to grow and replace these energy reserves after rain, then these reserves run down. This reduces perennial grass resilience and increases the risk of them dying.
This story, about a kangaroo proof boundary fence, illustrates why controlling kangaroos is in the best interest of graziers managing carbon flows to maximise profits and environmental outcomes. This message is even more important in the face of increasingly unreliable rainfall and discussion about drought policy.
LANDSCAPE RESPONSE AFTER A KANGAROO PROOF BOUNDARY FENCE WAS BUILT
Photo 1 was taken on a property west of Blackall, Queensland, Australia at the start of October 2018. The boundary fence in the photo is kangaroo proof. It was built around the entire 80,000 acres (32,000 ha) of the property in 2010 and then the kangaroo population was reduced to a population similar to the size found at the time of European settlement. The photo highlights that cattle numbers are well managed to ensure ground cover is maintained.
Photo 2
Photo 3
Photo 4
Photo 2 is looking across the kangaroo proof boundary fence from another neighbour’s property. There was good rainin February/March 2018 and then no rain was recorded during the six months prior to these photos being taken at the start of October.
The cracks in the ground in the foreground highlight that the soil is very dry because of no rain for a long time. However, photo 2 highlights that drought arrives sooner for some producers than others, and the arrival of drought comes down to more than just rainfall.
Photo 3 was taken about 400 metres (440 yards) off the boundary fence in photo 2. It highlights that there can be standing pasture well after it has rained, if the pasture is allowed to grow after rain in the first place and then what grows is not over consumed too early, be it by kangaroos or cattle.
Photo 4 was taken on a third neighbour’s property looking back at the kangaroo proof boundary fence. The boundary fence is at the top of the photo on the other side of the council road. The yellow at the top of the photo is thick grass just like in the other photos.
The foreground highlights that the good February/March rain only grew some annual grass and weeds in this area, because perennial grasses are missing. A paddock that has lost perennial grasses due to ongoing grazing pressure after rain by cattle or kangaroos, will always go into drought quicker.
INSIDE IDALIA NATIONAL PARK WHERE THERE ARE KANGAROOS BUT NO SHEEP OR CATTLE
Photo 5: A fenced area inside Idalia National Park west of Blackall at the start of October 2018
Photo 5 was taken at the same time as photos 1 – 4. It was taken inside Idalia National Park that joins the property in photos 1-4.
This fenced off area inside Idalia National Park documents the ability of kangaroos to shut down carbon flows into the landscape, in exactly the same way that poorly managed sheep and cattle shut down carbon flows. While no soil samples have been taken, judging by the vegetation, it is to be expected that soil carbon would be higher in the fenced off area.
Photo 6: The Idalia National Park exclosure nine years earlier
Photo 6 is a photo I took of the Idalia exclosure on 14 November 2009. The commercial property has regenerated following the building of the kangaroo proof fence in 2010 and kangaroos being brought under control, but the National Park has not changed from 2009 to 2018, and is still degraded unfortunately.
Photo 7: Another exclosure in Idalia National Park on 14 November 2009
I took photo 7 to highlight that the pattern of land degradation was the same in the National Park, regardless of soil type.
There was good rain at the start of 2009 but it meant little for carbon flows in the park, except for inside the exclosures. The National Park exclosures were the catalyst for the producer to build the kangaroo proof fence in 2010. They demonstrated what the true potential of the landscape was and what he could aim for if he built the fence. The producer could see that kangaroos were eroding his Natural Capital. He has always been on the cutting edge of change and understood that it is management of carbon flows that underpins Natural Capital.
If kangaroos keep hammering a patch of landscape, in the end plants start to die. As some plants die, this increases the grazing pressure on the remaining plants and so the downward spiral continues. Plants are protected by how many mates they have to share the grazing pressure.
It is carbon flows introduced by plants that feed the soil microbes necessary for keeping the soil well-structured and fertile. Plants fail first, then the soil fails, because there are reduced carbon flows to keep the soil functional.
MAN-MADE WATERING POINTS CREATED THE PROBLEM
Kangaroos lived in harmony with the landscape prior to European settlement, but with the introduction of artificial watering points, we changed all that and dramatically increased the population of kangaroos.
Pre-European settlement, when surface water dried up during dry times, kangaroos had to move on or perish. In inland Queensland, it is suggested that up to 80% of kangaroos would perish in times of drought.
When rain arrived the landscape had to regenerate again. Nature made sure there weren’t too many animals to impact the regeneration phase.
During dry times when there was little permanent water in the landscape, the aboriginals and kangaroos all had to move back to the only permanent water. This made the kangaroos more vulnerable to being killed. The creek that ran through my Cunnamulla property that I sold in 2002 was called “Widgeegoara” by the aboriginals. Widgeeoara means “turn back, go no further” i.e. head back to the Warrego river 75 km (45 miles) away, which is where the only permanent water was.
THE BLACKALL PRODUCER FOCUSED ON WATER FIRST
Photo 8: Water available for cattle but not kangaroos
The Blackall producer’s first attempt to overcome the problem of excessive kangaroos was to remove water troughs and put in tanks that the cattle could drink out of but the kangaroos could not access. A case of taking things back to the way they were before European settlement. The tanks were installed in 2002.
While the tanks did lead to an improvement in the landscape and more than paid for the investment, they only supplied partial control of grazing pressure from kangaroos.
Kangaroos have evolved to cope with Australia’s climate that is the most variable in the world. They release very little water from their body as urine.
Depending on the time of year and the moisture level of the grass, the kangaroos on the Blackall property were drinking about every five days prior to the removal of the water troughs. While some kangaroos were forced to move on after the installation of the tanks, others were going to man-made waters elsewhere and then returning.
Rain that didn’t produce surface water, but did increase grass moisture enough for kangaroos to function, also allowed them to return to the property.
The producer finally accepted that building the fence was the only way he could return his property to pristine condition.
GRAZING PRESSURE LED TO WOODY WEEDS REPLACING PERENNIAL GRASSES, THIS IS NOW REVERSING
Pre-European settlement, wildfires played a role in stopping excessive encroachment of woody vegetation into the landscape. The other part of the equation was the ability of healthy perennial grasses to out compete germinating woody seedlings for water and nutrients. This is why it is so important to keep perennial grasses healthy to maintain the correct balance of a landscape.
Photo 9: Phase one of regeneration – the arrival of a perennial grass plant to act as a seed source (October 2018)
Photos 10 and 11: Phase two of regenerations (October 2018) and abundant seed being produced and collected by ants
As we all know, you can’t get regeneration without seed. Before the kangaroo proof boundary fence was built, there was little perennial grass seed being produced on the hard soils. This was because the population of perennial grasses had become very low. Because of the low perennial grass population, the number of kangaroos present, even when cattle were removed, were able to stop most seed sets and also apply too much grazing pressure on perennial grass seedlings to allow them to establish.
After the kangaroo population was reduced to a sensible number, it was a case of waiting for perennial grass plants to establish in degraded areas and become a seed source to regenerate the area around them.
Photo 9 shows the arrival of a perennial mitchell grass plant. Looking at the size of it, it is not very old, so is a seed source that has arrived in the recent past. After over fifteen years of observing this area, photo 9 was a quantum leap forward. This is the first phase of regeneration.
The good soils on the property have regenerated as photos 1-4 show, however the fragile soils that had become more degraded, are taking longer, which is normal.
EXCLOSURES CONSTRUCTED ON THE BLACKALL PROPERTY PROVIDED FURTHER EVIDENCE
Apart from the exclosures built in Idalia National Park, exclosures were also built on the Backall producer’s property. These supplied the producer with further understanding of the true impact of kangaroos.
A total and a partial exclosure was built on the producer’s property in close proximity. The partial exclosure was built with running wire and kept out commercial animals, but kangaroos could get in. The total exclosure was built with netting and excluded both commercial animals and kangaroos.
Photo 12: A netting and running wire exclosure built on the Blackall property
Like in the national park, the total exclusion improved the landscape back to pristine condition. However, kangaroos getting into the partial exclosure maintained it in the same condition as the paddock outside, as photos 12 and 13 show.
Photo 13: October 2002 and the pattern is still the same
For years, the running wire exclosure demonstrated that kangaroos will over-ride decisions made to improve livestock management. In 2009, when I took photos of the Idalia National park exclosures, inside the running wire exclosure on the property was still the same as the rest of the paddock.
Photo 14: Running wire exclosure October 2018 – It took the building of the kangaroo proof boundary fence to regenerate the running wire exclosure
With the building of the kangaroo proof fence around the entire property, there was a dramatic change inside the running wire exclosure. The landscape inside it has now totally regenerated and is in the same condition as the netting one that showed the true production potential of the landscape many years earlier.
The property now has great ground cover as far as the eye can see, and when photo 14 was taken at the start of October 2018, the Blackall district was drought declared.
The ability of a paddock to produce carbon flows from rain is the true measure of paddock resilience. In photos 1-4, resilience started at the kangaroo proof fence.
To my surprise, the day I took photo 14, I noticed that there was a green tinge in the stems at the base of the Mitchell grass in this area, six months after the last rain. The green tinge indicated the landscape was ready to respond to a marginal fall of rain and produce some carbon flows, – a true sign of resilience.
The slightly green stems represented healthy plants sitting in a functional soil that must have had some moisture at depth, which the plants with deep roots had managed to reach.
KANGAROOS CAN SHUT DOWN MORE GROWTH THAN THEY ACTUALLY EAT
Traditional discussion will allocate a percentage of total grazing pressure to all the different animals present based on how much they eat. A kangaroo is considered to eat less than what a sheep eats, and this is totally true. However, this approach misses the point if you are a big picture person i.e. a systems thinker.
It is not just what a kangaroo eats. There is also the issue of the amount of growth they shut down i.e. reduction of carbon flows into the paddock. They do this by getting through normal fences and turning up when plants are trying to grow after rain. Prior to European settlement, this was not an issue because their population was much lower.
Scientists I met in South Africa in the 1990’s, put a figure on lost growth from animals eating plants when they are trying to grow after rain. They said that resting average pastures for three to eight weeks after rain, increased pasture production by 30 – 80%. There would also be a proportionate increase in the amount of carbon going under ground to build roots and being released as liquid carbon in the form of root exudates for soil microbes.
THE NUMBER OF STOOLING POINTS INFLUENCES CARBON FLOWS AFTER RAIN
Apart from protecting the soil from wind and water erosion, there is another practical reason why ground cover should be maintained as high as reasonably possible and not eaten right down to ground level or cut off near the base as kangaroos can do. The number of stooling points increases with pasture height and the more stooling points there are on stems, the quicker a plant can bulk up after rain.
Photo 15: Stems cut off by kangaroos and left on the ground
Photo 15 demonstrates that kangaroos have the ability to cut off stems at the base of perennial grasses, using their protruding scissor teeth. When they do this, they are not eating the stems, simply removing them to get at more digestible parts of the plant.
Photo 15 is a good example of kangaroos removing stooling points and reducing the capacity of perennial grasses to respond to rain. It is ironic that the photos were taken after 20,000 acres (8,000 ha) had been locked up for a month after rain to increase ground cover on a Cunnamulla property. Even more ironic that this was the last pasture growing rain before a drought set in.
On my Cunnamulla property, I had a formed up road in one section of the narrow laneway through the property. Because it was possible to drive at 100 km per hour (60 mph), I often surprised kangaroos just before dark when they came out to feed. As they madly hopped along the fence outside the window, I sometimes noticed a grass stem sticking out of their mouth. In their haste to get away they had obviously not released the stem from between their two teeth, which they had just cut.
The Blackall producer was better able to maintain stooling points after the boundary fence was built, because he only had to focus on adjusting cattle numbers depending on how the season was traveling.
Prof Bob Miles, a retired rangeland scientist sent me this very interesting information, “Kangaroos have protruding dentition. That is their teeth point forward and can therefore eat shoots off below ground level. Sheep and cows cannot. Cows have a big nose so only eat a few centimetres above the ground. Sheep open their gums and eat at ground level”.
KANGAROOS APPLYING GRAZING PRESSURE AFTER RAIN CAN PROLONG DROUGHT
Photo 16: Rain not increasing ground cover outside a kangaroo proof fence at Cunnamulla
Photo 16 is a kangaroo proof fence built around 15,000 acres (6,000 ha) north of Cunnamulla. On the left hand side of the fence, 13,000 kangaroos were removed from the 15,000 acres over three years after the fence was built.
The left hand side of the fence highlights the ability of the property to now respond to rain during dry periods.
It is when grass is short, that grazing pressure has to be really well managed.
CSIRO RESEARCH COMPARED KANGAROOS AND SHEEP FOR LANDSCAPE IMPACT
In the late 1990’s, CSIRO rangelands scientist Allan Wilson told me that he was involved in grazing trials to quantify the true impact of sheep and kangaroos on the landscape. To do this, they put only kangaroos into a fenced off area and likewise only sheep into a fenced off area. He said that the kangaroos did more damage than sheep when contained.
My memory fails me on the exact stocking rate, but I think they stocked the fenced areas on the basis that a kangaroo eats 60% of what a sheep eats.
GOVERNMENT POLICY IS PROTECTING SOME KANGAROO SPECIES WHERE THEY DIDN’T PREVIOUSLY EXIST
Photo 17: This grey kangaroo is now in an area where the species did not exist at the time of European settlement
Photo 17 was taken recently on my former Cunnamulla property that I sold in 2002. Unfortunately it is suffering a terrible drought, worse than anything I went through.
My father was born in 1914 and grew up in the Cunnamulla area. He told me there were no grey kangaroos in the area while he was growing up and others of his vintage confirmed this to be true. Now, grey kangaroos account for the bulk of the kangaroos in the area.
It was the introduction of man-made watering points that has allowed this non-migratory kangaroo species to move further inland and establish where they were not before. This has placed unprecedented grazing pressure on this inland country, which had traditionally been populated by the migratory red and blue kangaroo.
Continuous grazing is the worst form of land management, yet this is exactly what these grey kangaroos are responsible for, because of their small range.
Government policy is now protecting this grey species of kangaroo by stipulating that females can’t be harvested below a minimum body weight. This legislated weight is higher than the weight they have to reach to reproduce i.e. they are reproducing before they can be legally be harvested.
Unfortunately, government policy based on a lack of understanding of this area’s history is helping to degrade the landscape. Go to any forum today discussing policy and everybody is talking about the need to look after “Natural Capital”.
DROUGHT POLICY NEEDS TO LINK KANGAROOS WITH EARLIER ARRIVAL OF DROUGHT
With the current extensive drought in Eastern Australia, there is a lot of debate about drought policy and where changes need to occur.
Management that increases carbon flows, from any rain that falls, delays the arrival of drought as all the photos show. This is a good starting point for improving policy.
Photo 18: Kangaroos consuming saved groundcover
Photo 18 is a paddock at Cunnamulla that was locked up during the 1990’s to maintain ground cover for future use. However it was completely eaten out by kangaroos as the kangaroo dung confirms.
Unfortunately, kangaroo policy is eroding drought policy and this is costing the broader community, because drought subsidies are larger than they need to be.
When the whole of his district was drought declared in October 2018, the last thing the Blackall producer was thinking of was a drought subsidy.
SHARING THE BLAME PROPERLY
Prof Brian Roberts of the University of Southern Queensland “Land Use Study Centre” explained to me years ago why there are misconceptions around the impact of different animals on the landscape. He said that it’s the animal in the landscape last that is blamed for the outcome, however, he pointed out that the ones that precede the ones there last, are also responsible for the final outcome.
Photo 19: Evidence of a high kangaroo presence
Photo 19 was taken on the Blackall property prior to the fence being built. If this photo had sheep or cattle in the background, to the untrained eye, it would make them responsible for the state of the paddock. However the huge amount of kangaroo dung on the ground tells a different story.
KANGAROOS INCREASE METHANE PRODUCED BY CATTLE
The cornerstone of reducing methane produced by cattle and sheep is to improve the digestibility of their diet.
A kangaroo researcher from the University of Sydney told me that kangaroos are more selective in what they eat than even sheep are. When kangaroos remove the most digestible parts of the pasture, what is left behind for cattle to eat is less digestible. This results in cattle producing more methane per kg of production because they are on a lesser quality diet. What kangaroos are doing is changing the carbon:nitrogen ratio of what is available for cattle to eat.
A new understanding of livestock methane is now developing. Climate scientists world-wide are starting to realise that provided the ongoing methane emissions from sheep and cattle in any country are stable year after year, in other words, animal numbers are not increasing, then these ongoing emissions do not change the climate. Methane is a short term gas (life of 12 years), so the methane being produced today is only replacing the methane produced 12 years ago that has now broken down. Hence todays emissions are not increasing the atmospheric balance of methane. Put simply, these ongoing methane emissions are not changing the net balance of greenhouse gases in the atmosphere, the basis of climate change. However, any management that leads to a reduction in methane emissions is actually reversing climate change.
KANGAROOS CAN TAINT PASTURES FOR OTHER ANIMALS
Kangaroos have evolved to be very efficient in their utilisation of water. As a result, they have a very concentrated urine. Their urine is so concentrated that it can contain crystals in it and not much water.
When I was growing up my father told me that sheep would not eat grass that had been heavily grazed by kangaroos, because it was tainted by kangaroo urine. He said that it remained tainted until a shower of rain removed the smell.
I had to wait until the 1982 drought, before I was supplied with evidence that proved my father was spot on with what he knew. The 1982 drought was one of worst droughts of the twentieth century and I only had 10% of the sheep left on the Cunnamulla property, with the rest on agistment.
Near the homestead was a small area of buffel grass in a dormant state. It is a prolific growing grass, so I watered it for the few rams not on agistment. It was the middle of summer, so the buffel responded quickly. It was the only green grass on 50,000 acres. After the rams had been eating it for three days, the kangaroos discovered it. After that the rams never ate it again, although they were often foraging near it. Apart from all the kangaroo dung, there were marks on the ground everywhere from them dragging their tail as they ate. I then had to build a kangaroo proof fence around the area and water some more grass.
THE ATMOSPHERE DOESN’T UNDERSTAND THE DIFFERENCE BETWEEN SHORT AND LONG-TERM CARBON
The large volume of dry grass inside the kangaroo proof boundary fence shown in photos 1-4, represents a lot of carbon that is not in the atmosphere, remembering that dry grass is 45% carbon. Roots are about 45% carbon and inside the fence, there would also be a much higher root volume.
A lot of climate policy is all about processes, not outcomes unfortunately. Because of carbon trading, we are focused on only the long-term carbon present in the landscape. However, the atmosphere does not understand the difference between what we call short-term carbon and long-term carbon. It only understands that if carbon is in the landscape, then it can’t be in the atmosphere.
Since the fence was built, the Blackall producer has been able to maintain ground cover by being able to manage what grows and what is being eaten by adjusting cattle numbers. While the actual amount of ground cover does vary over time because of rainfall, his minimum level of ground cover is now much higher since he built the fence. This minimum level of ground cover represents “long-term short-term carbon” when other paddocks in the district are spending time bare.
THE SUBTLETIES ARE EASY TO OVERLOOK
The business model of the Blackall property is buying small steers and then growing them up and selling them as fat bullocks. Every time bullocks were sold and replaced with small steers, this reduced the grazing pressure, because the small steers only eat a third of what bullocks eat.
Before the fence was built, one particular year, kangaroos had a much greater impact on the business than the actual amount of pasture they ate would suggest.
Prior to the arrival of extra kangaroos, the season was starting to deteriorate but he had enough suitable grass in the pasture to fatten the bullocks on the property and sell them in October. The arrival of the kangaroos stopped this happening. As a result, he had to hold the bullocks and wait for the wet season to arrive, which did happen in January. The bullocks were eventually sold as fats in April.
The kangaroos had cost him six months production, because not being able to sell the bullocks as fats in October, meant he could not enter the next production cycle with small steers.
There was also the issue of the higher grazing pressure on the landscape that the held over bullocks applied, that replacement small steers would not have applied, given they only eat a third of what bullocks eat.
There are a lot of subtleties, and not just simple consumption figures, when discussing the impact of kangaroos.
IS A KANGAROO INDUSTRY IN THE BEST INTERESTS OF THE ECONOMY?
It is true that the kangaroo meat and hide industry is producing export income and providing jobs. However an alternative option for Australia is to move away from kangaroo harvesting and concentrate on exclusion fencing to reduce kangaroos to pre European settlement numbers, and so increase total export income via much increased sheep and cattle production.
If a cost benefit analysis was conducted, it is very likely that increased sheep and cattle production would produce much more export income than the total value of the current kangaroo industry. The improvement in the environment (Natural Capital) and less human stress from drought also needs to be valued.
What is not often mentioned, is that the digestive system of sheep and cattle is more efficient than that of kangaroos.
A person in a recent ABC Landline program said that we need to utilise kangaroos more as a resource, especially given that they don’t have a carbon footprint. A quick look at the exclosures in Idalia National Park and those on the Blackall property, suggest that kangaroos do have a carbon footprint.
THE BEST OF BOTH WORLDS WITH THE BOUNDARY FENCE?
It is pretty obvious that the landscape was not fully functional before the kangaroo proof boundary fence was built around the Blackall property. Now it would be interesting to consider how the current producer’s landscape, that is now functional, is performing versus the one that existed pre European settlement, which was also functional.
While it is impossible to be conclusive in comparing the present landscape with the pre European settlement landscape that we did not witness, except for explorer reports. Others I have spoken to agree that it is likely that the Blackall producer is operating at a higher level, i.e. the level of carbon flows produced over time by his production system, for cattle to consume, would be higher than the carbon flows produced by the landscape pre settlement.
Putting aside the aspect of reliable introduced water, the current fenced landscape of the producer has a greater potential to maintain animals over time than the one in the past because of two factors that have changed: wild fires and moribund (rank) grass.
Fire is the more influential factor. Wild fires consume grass that could have been available for cattle to eat. It is known that these fires travelled great distances in the past because of no machinery to put them out. Pre European settlement, the pastures were able to recover from these fires that burnt grass down to ground level, because grazing pressure was not high in the recovery period. However these recovery processes take time and are periods of lower production. Especially if a wild fire precedes a run of dry years.
Low grazing pressure in the past would have, at times, produced moribund grass that is inefficient at introducing carbon into the landscape, just like over grazed unhealthy grass is inefficient at introducing carbon. Moribund grass is very inefficient at using available water. By removing the top off the grass all the time, the producer’s cattle are stopping it going moribund.
Getting back to basics, when graziers let animals, including kangaroos, harvest carbon flows too early following rain, they interfere with the biophysical conduit (leaves) that are responsible for introducing carbon into the landscape. The Blackall producer was only letting cattle harvest the “surplus”, not the means by which a usable surplus is generated. Also, he was not harvesting to ground level the way a fire does.
CONCLUSION
The photos taken inside Idalia National Park and on the Blackall property over time, highlight that kangaroos may cause more environmental damage than existing public debate suggests.
Rangeland scientists are aware that plagues of kangaroos are frustrating paddock management.
Kangaroos influence soil carbon levels because of their ability to get through fences and reduce the flow of carbon into the landscape when grasses are trying to grow after rain. They also increase the amount of methane produced by sheep and cattle because their very selective consumption of pastures changes the carbon:nitrogen ratio of the diet available to sheep and cattle.
At a policy level, consideration needs to be given to the ability of kangaroos, as an uncontrolled animal, to impact paddock resilience. This is resulting in the early arrival of droughts.
Australia would probably be better off financially and environmentally if properties were fenced to protect them from kangaroos, and the kangaroo harvesting industry slowly wound down as more fences are built. This is not suggesting that there should not be kangaroos on properties, instead a token number like there was at the time of European settlement.
