REGENERATING OUR LANDSCAPE

Sharing information on innovative leading performance in managing Australia’s natural environment to encourage the wide adoption of regenerative landscape management techniques by our farmers and land managers - and why this is essential.

ALAN LAUDER ON WHY CARBON FLOWS? Edible shrubs supply more reliable carbon flows

Thursday, December 14, 2017

When carbon moves around a grazing paddock, above and below ground, nitrogen goes for the ride. The amount of nitrogen partnering carbon at any point in time is known as the carbon:nitrogen ratio. The issue for producers is that nitrogen sometimes chooses to part company with carbon before it moves into sheep and cattle. This happens as grass matures and dries out.


Pasture connoiseurs know what they are looking for in a good balanced meal.

However, this is not a problem with edible shrubs such as old man saltbush or fodder trees like leucaena. Their nitrogen (protein) content over summer is much more constant because they have the ability to remain green. In the case of saltbush, it grows in both summer and winter and is not affected by frosts, so maintains its nitrogen/protein year round. 

Edible shrubs and fodder trees have the ability to draw on deep moisture not available to the grasses.

Increasing the pathways by which carbon can flow into the paddock


The four plant types livestock rely on for energy and protein -annuals, perennial grasses, perennial edible shrubs and fodder trees.

There are different pathways by which carbon enters the paddock.

At one extreme, we have the fast growing annuals with shallow roots that utilise the surface moisture.

At the other extreme, are perennial edible shrubs and fodder trees that transfer the use of rain further into the future. They can grow under adverse conditions. They maintain carbon flows over time because of their deep roots sourcing moisture deeper in the landscape.

Leucaena has the added advantage of directly introducing some nitrogen into the surrounding soil.

The importance of “green pick” (green leaf)    

Animal production is very sensitive to small increases in green pick from herbs, grasses, palatable shrubs and fodder trees. A little goes along way. Small increases of “green pick”, when it is in short supply, can “double production”. (Source: CSIRO Rangelands Series Sheet No 7.)

The graph above demonstrates how wool production increases from one to three kilogram per head with a very small increase in “average supply of green leaf”. At first glance, the production curve appears to go straight up then to the right. In fact, it is leaning a little to the right as it rises quickly. This indicates that production is increasing quickly while supply of green leaf is only increasing marginally.

Perennial edible shrubs and fodder trees are both important sources of “green pick” which is critical for production in dry times.

Sheep and cattle select to maximise “green pick”

Proportions of green grass, dry grass, forbs and shrubs in the diet of steers grazing between November 1977 and May 1978, in Alice Springs, as seasonal conditions varied.(Source: Squires and Siebert, 1983.)

In the graph, the consumption of shrubs (shown at the top of the graph) is going up and down depending on the availability of green grass.

When cattle couldn’t source “green pick” from green grasses, they sourced it from shrubs.

Note how the shrub consumption decreases briefly in April when there is a short-term increase in green grasses.

In dry times, the rumen microbes in sheep and cattle rely on shrubs and fodder trees to supply protein/nitrogen for them to build their little bodies. Then they can break down poor quality (low protein/nitrogen) grass and empty the rumen quicker.

The grass is drying off while the planted old man saltbush is still full of protein/nitrogen and producing carbon flows as it keeps growing.

Using old man saltbush plantations for resting pastures after rain

In the mid 1990’s, the Federal Department of Agriculture became aware that I was suggesting that old man saltbush (OMSB) plantations could be used as somewhere to put livestock, to allow resting of pastures for a short period after rain – the time when the bulk of the carbon flows into the paddock. I was subsequently funded to conduct a $272,000 Drought Regional Initiative project to perfect the use of OMSB for this role.

The drought resistance of OMSB means it is always available for this role, especially important when an isolated fall of rain arrives during dry times or when rain arrives at the end of a drought, when pastures are bare. 

Seeing OMSB plantations as a management tool for resting pastures after rain is a paradigm shift for those who see it solely as a drought reserve. A case of using it in the mud and not the dust.

Methane reduction

Nitrogen content drives digestibility and unless the digestibility of the feed can be maintained above about 50%, then methane emissions skyrocket.

Edible shrubs and fodder trees speed up the flow rate of pasture (carbon) through the rumen of livestock in dry times, when the nitrogen content of standing grass is low. They increase the flow rate by changing the carbon:nitrogen of the total diet, which lowers methane emissions per kg of production.

With the cattle at Alice Springs, if the shrubs had not been available during the times when they were eating them, methane emissions per kg of production would have really risen.

Australia has the most variable climate in the world which appears to be becoming even more variable. Reducing the effect of this variability is the best way to reduce methane emissions. This is where edible shrubs and fodder trees fit in.   

Resting pastures after rain, increases pasture resilience. Resilient pastures are greener over time, which is another way to reduce the effect of a variable climate.

Conclusion

Edible shrubs and fodder trees hold nitrogen with carbon longer. If present, they are the only spot where adequate nitrogen is held in the pasture when grass has lost its nitrogen.

They also transfer the use of rain further into the future i.e. they generate carbon flows when it is not raining.

This discussion is a bit like the relay runner passing the baton i.e. passing the baton to the next species responsible for running nitrogen through your sheep and cattle. Your race is over if there is nowhere to pass the baton.


Alan Lauder

The column will start again at the end of January 2018.



ALAN LAUDER ON WHY CARBON FLOWS? Financial analogy

Thursday, December 07, 2017

Short term carbon is the fast moving carbon and long term carbon is the slow moving carbon. To put fast and slow moving carbon into a commercial analogy, think of cash flows versus capital.

Cash flows keep you in business, just like the fast moving carbon that keeps you in business too. Think of the slow moving carbon as really part of your capital base, just like cattle yards and buildings.

The cash flow aspect

The fast moving short term carbon makes money for you because it feeds all the life in the soil that keeps the soil productive AND feeds sheep and cattle. Remember cattle are 18% carbon, with all this carbon coming from the fast moving carbon. It is the faster moving carbon that builds larger root systems in plants so that they can access more moisture and nutrients to grow. It is central to plant energy reserves that determine how well plants can come out of dormancy.  The ability to respond to isolated small falls of rain is especially important in dry years when getting something to grow is critical.

Ground cover is fast moving carbon as is organic matter that supplies nutrients to plants.

The capital aspect

Humus in the soil is long term carbon which is the by-product of microbial activity (consumption).

This slow moving long term carbon is important for a different reason. It provides long term resilience by holding resources. It is essential for increasing the “storage” of both water and nutrients in the soil for plant growth.

A lot of literature uses the terms “organic matter” and “humus” very loosely, as if they were the same thing, which they aren’t. Organic matter is the raw material for humus.

Humus helps hold water in the root zone. Because humus is smaller in particle size than clay, it has a greater water holding capacity than clay. Smaller particles have a higher surface area to volume, which increases holding capacity. This also explains why sand, which has large particles, has a poor water holding capacity.

Because humus is highly charged, it will aggregate many particles into stable aggregates. This leads to better soil structure and it is resultant pores that hold extra water containing the soluble nutrients like nitrate nitrogen.

Also, humus is the habitat for long-term populations of microbes.

The cation exchange capacity (CEC) is a measure of soil fertility and quantifies the volume of mineral elements that the soil can hold and make available for plants to use. Humus has a higher CEC than clay particles, so is better at keeping nutrients in the paddock.

How to reduce carbon flows & cash flows

Management that leads to a reduction in carbon flows from any rain that falls, also reduces cash flows.

Sheep shutting down carbon flows after rain (Photo: Patrick Francis)

The above photo was taken after 30mm of rain. This is a grazing operation that will be out of production soon. The question has to be asked, when should carbon flows be harvested? When possible, pastures should be rested for a short period after rain to maximise carbon flows into the paddock, like in the foreground. In other words, graziers need to let sheep and cattle only harvest the surplus, not the means by which a usable surplus is generated.

Moribund pasture bringing in little carbon after rain

Letting animals over consume plants when they are trying to grow is one way to reduce carbon flows, however, when perennial grasses are not exposed to grazing, they become moribund. Moribund grass introduces a lot less carbon than grass correctly grazed.

Capitalising short term carbon

It is very hard to establish a figure, but it would appear that about 2% of long term soil carbon leaves the system each year i.e. flows back to the atmosphere. It also appears that about 2% of carbon flows find their way into the long term pool.

All businesses have to maintain capital infrastructure. Think of carbon flows as maintaining the pool of long term soil carbon. If carbon flows are really well managed, this can lead to a capital gain if more carbon moves into the long term pool than moves out. Of course, there is a limit to how much long term carbon the soil can store.

Another perspective

When I ran the “financial analogy” past Ruaridh Petre, he responded by broadening it further, Life on earth is an economy that runs on carbon. The more busily plants and microbes trade carbon molecules, the more prosperous the ecological economy becomes. Also, you’ve got to use carbon to store carbon.”    

Conclusion

Erosion is an immediate reduction in earning capacity, because it removes both short term and long term carbon.


Next week's discussion: "Edible shrubs provide more reliable carbon flows"

Alan Lauder

ALAN LAUDER ON WHY CARBON FLOWS? The structural role of flowing carbon

Wednesday, November 29, 2017

Everybody knows the presence of carbon is important for soil structure, however, it also has a structural role. This comes back to carbon being the main building block of pastures.

By structural role, I mean the way paddocks are more water efficient and have increased capacity to capture resources when plants are physically present.


Root response to different grazing pressure

The wick effect

Carbon has a structural role as part of plant the roots. Roots, which are 45% carbon, act as “wicks” to take water down through the soil profile, especially important with harder soils.

This is achieved by water travelling down beside roots. Better managed plants, with more extensive root systems, distribute water faster through the soil and to greater depth.

Resting pastures for a short period after rain increases carbon flows for root construction, which in turn improves the infiltration of future rain.

With perennial grasses, the roots grow and die back. This results in cavities where roots have previously been. These cavities are very effective for water infiltration.

Roots help secure nitrogen

Where pastures are not fertilised, the nitrogen present in the soil originates from the earth’s atmosphere, where it makes up about 78% of the air. Each hectare of the earth is covered by about 84,000 tonnes of nitrogen in the atmosphere.

Nitrogen comes in with rain, so infiltration determines plant available nitrogen from this source. In the tall grass savannahs of the Northern Territory of Australia, each year rain brings in 2 kg of nitrogen per hectare. To put this into perspective in this area, at the end of the growing season there is 10-15 kg of nitrogen in standing grass, which is low compared with more fertile areas.  

There seems to be a trend towards more intense rainfall events, which is why improving water infiltration is even more important. 

Lifting wind & shading

Have you ever given any thought to why clothes on the line dry quicker on a windy day than on a still one? Going back to basics, moisture is released from the wet clothes into the drier air around them. When the immediate air beside the clothes is saturated, no more moisture is released from the clothes. The wind dries the clothes because it blows away the moist air and replaces it with drier air, which then absorbs more moisture from the clothes.

The clothes line principle is central to another structural role of carbon. Standing plants lift wind off the soil surface which slows the drying of soil.   

Shading by plants is an important component of water use efficiency, as it slows evaporation and makes more water available to plants.

Maintaining the population of soil microbes over time

A lot of soil microbes are like perennial grasses, in that they have to go into dormancy when conditions are not favourable.

When the soil dries quicker than it should, this does not give soil microbes time to go through their normal process of going into dormancy and so they die.

The soil remaining dry for a long time during droughts is not an issue for dormant microbes. Microbes found in the tombs of Egypt have been reactivated.

Collecting dew

Another structural role of carbon is collecting dew in some environments. This relies on the surface area of grass being adequate.

German scientist, Dr Wihelm Ripl explains why plants are responsible for greater availability of water to the landscape, “Water vapour in the lower atmosphere close to vegetation, even without a single rain event, can be precipitated by leaves, needles and other structures with high surface to volume ratios. The result is a lowering of surface energy and a warming of these structures.”

In the case of frosts, for moisture to accumulate on the soil surface, there has to be enough moisture frozen then thawed as the sun rises. In an area suffering the driest winter in years, I observed that there was regularly moisture on the ground at the base of plants after the sun had risen. This phenomenon was only occurring where the grass was thick and tall. It was actually maintaining some green leaf at the base where it was protected from frost.

Conclusion

The structural role of carbon relies on the faster moving carbon residing in plants, which in turn reflects the management of carbon flows from what rain does arrive.

Management that leads to better water infiltration via increased roots and then slower drying of the soil surface due to wind being lifted, increases germination.

Roots play a very important role in Reef protection. Water has volume and if it gets together and gathers speed, then that is when it does damage by eroding soil and carrying nutrients into waterways. Getting more rainfall into the soil reduces this problem. Also, more standing pasture helps keep water apart and from gathering speed.

Next week’s discussion: “Financial analogy”

Alan Lauder

ALAN LAUDER ON WHY CARBON FLOWS? Speeding up the faster moving carbon for increased profit and reduced methane

Wednesday, November 22, 2017

Have you ever thought about why cows digest leaves faster than stems or why a leaf breaks down faster in the soil than a stem. Well actually, cows do not digest leaves/stems, nor does the soil break down leaves/stems.

In the case of cows, it is the microbes in the rumen (first stomach) that consume what they can of what the cow has swallowed. The cow then digests the microbes as their food source

In the soil, it is microbes, such as bacteria and fungi that have the first snack on organic matter, eating what they can. Other soil life such as protozoa and nematodes then consume the microbes as their food source, and they in turn are consumed.   

After entering plants, it is ongoing consumption from one living thing to the next that moves carbon through the landscape above and below ground. However, this consumption is very dependent on enough nitrogen being available.


The carbon in a leaf moves faster than the carbon in a stem because the carbon:nitrogen ratio is lower.

The carbon:nitrogen ratio

Last week it was explained that the relative amounts of carbon and nitrogen in different life forms, and their waste products, is referred to as the carbon:nitrogen (C:N) ratio.

Leaves have a higher percentage of nitrogen to carbon than stems i.e. lower C:N ratio. This allows microbes to multiply faster due to the higher availability of nitrogen. The faster microbes are able to multiply, the quicker the faster moving carbon starts to move.

Given plants (and trees) are the start of the above and below ground food chain in the paddock, the C:N ratio of pasture plants sets the speed of the faster moving carbon in the paddock that producers rely on.

The soil process – How nutrients in organic matter become plant available

It is the C:N ratio of organic matter that determines how quickly nitrogen is mineralised and made plant available again, as the following two diagrams demonstrate.

For materials with a low C:N ratio such as Lucerne, the breakdown will begin almost immediately, because there is plenty of nitrogen around, and this nitrogen is needed by the bugs to make proteins. The more they multiply, the more nitrogen needed.

In fact, there is usually more nitrogen in the Lucerne than is required, so some is released into the soil and can be used by plants.

However, for say oat trash with a higher C:N ratio, nitrogen is usually not released upon decomposition, and may not become available for many months. In fact nitrogen from the soil (which otherwise would be available for plant growth) is usually needed by the decomposing organisms to complete the job of breaking down the oat trash, i.e. the soil organisms remove nitrogen from the soil as they need proteins to build their bodies.

Death of soil microbes is an absolute necessity as part of nitrogen mineralisation.  The C:N ratio of bacteria and fungi, the first consumers of organic matter, is lower than the soil life that consumes them. Hence, the unneeded nitrogen is released to the soil and becomes available to plants.

Looking at the two examples, 60% of the carbon consumed has been released (respired) back to the atmosphere during consumption. The rest is now in the soil microbes.

The cow process – Getting sheep and cattle to market sooner & reducing methane

Because the microbes in a cow’s rumen have the same requirements as those in the soil, leaves, which have a lower C:N ratio than stems, move faster through a cow. Likewise, green grass has a lower C:N ratio than dry grass, so moves faster.

The reason sheep and cattle are selective in what they eat, is that they intuitively know that microbes in their rumen (gut) multiply faster with a higher nitrogen diet. The faster rumen microbes multiply, the faster the cow grows.

Hydrogen is produced in the rumen as microbes consume the gut fill. Methanogens are microbes living in the rumen that remove this hydrogen by joining it to carbon to form methane (CH4), which the cow burps out.

If the rumen is emptying slower because the microbes are multiplying slower, because nitrogen levels are lower, the methane outcomes are worse. There is actually less methane produced each day, but because the cattle take a lot longer to get to the meatworks, the methane produced in total is more i.e. more per kg of production. 

Ways to lower the C:N ratio

Resting paddocks for a short period after rain increases the percentage of leaves to stems.

This short rest after rain increases carbon flows which increase plant energy reserves and root volume, which in turn results in pastures being green for a higher percentage of the year. 

Ensure animals don’t eat out the more palatable lower C:N plants.

As a general rule, higher quality pastures (lower C:N ratio), result in manure that is broken down quicker in the soil.

Conclusion

There is a reason why a paddock is more productive when the faster moving carbon (short term carbon) moves faster. Everything that is joined to carbon, such as nutrients and energy, becomes available to sheep and cattle sooner. Also, increasing the speed of the faster moving carbon results in nutrients becoming plant available sooner.

Increasing the speed of carbon through ruminant animals like sheep and cattle increases profits by getting them to market sooner and reduces the production of methane per kg of production.  

From a “management” point of view, it is carbon flows that are important, but moreover, it is the speed of flows that is the critical thing for a rural producer.

Next week’s discussion: “The structural role of flowing carbon”

Alan Lauder



ALAN LAUDER ON WHY CARBON FLOWS? How carbon and nitrogen work together

Wednesday, November 15, 2017

We can’t fully understand the process of carbon movement from one life form to the next in a paddock, until we understand how nitrogen fits in.

When any living thing dies or is consumed, plants included, it becomes the food source for another living thing. All the nutrients and trace elements are important for the next consumer, but nitrogen is a key player. It has to be passed (along with carbon) in adequate quantities down the food chain to ensure ongoing life.

Put simply, nitrogen is always moving just like carbon is always moving. However, carbon can’t move from one life form to the next, driving production and landscape health, if there is not enough nitrogen to go with the carbon.

Carbon compounds provide energy and cellular building blocks, while nitrogen is a crucial component of proteins, necessary for cell growth and function. It is nitrogen that builds tissue. Nitrogen is a component of amino acids which are the building blocks of protein.

The carbon:nitrogen ration

How much carbon and nitrogen any life form requires, be it a plant, soil microbe, worm, insect or animal, is referred to as the carbon:nitrogen (C:N) ratio of that life form.

Suppose a plant sample is made up of 40% carbon and 2% nitrogen. Dividing 40 by 2, the result is 20. The C:N ratio of this material is 20 to 1, which means 20 times as much carbon as nitrogen. The ratio is often shortened and just written as 20.

Humans are 18% carbon and 2.5% nitrogen, so we have a C:N ratio of 7.2.

 

Variations in carbon:nitrogen ratios

Organic matter breakdown (consumption)

Organic matter consisting of deceased life or their waste products also has a C:N ratio, which indicates its value for consumption by soil life.

As a rule of thumb, a C:N ratio of approximately 25 is somewhat of a watershed. The further the organic matter is above this value (i.e. higher amounts of carbon per gram of nitrogen) the slower will be the rate of decomposition. On the other hand, with a C:N ratio lower than 25, the faster the rate at which organic matter decomposes. This is why, say Lucerne (C:N ratio of 12 - 15), doesn’t last long in the soil compared to wheat stubble (C:N ratio of 90 - 160).  

Improving pasture C:N ratio

As plants are the start of the food chains, above and below ground, their C:N ratio sets the scene for the efficiency of a grazing paddock i.e. how quickly consumption occurs in the paddock as one life form consumes another. For this reason, it is important to ensure that animals do not eat out the species with the lower C:N ratios.

We can improve the C:N ratio of plants through better management (i.e. higher carbon flows) that improves the fertility of the soil. In general it could be said that any specific plant type in a properly functioning landscape will have a higher nutritional value (including better C:N ratio) than one in a dysfunctional landscape of the same soil type. The protein level of wheat changes when fertiliser is added, which is another example of the principle. 

Conclusion

The C:N ratio is an important concept for producers to understand. The ratio is always being mentioned in scientific literature however it rarely seems to rate a mention in extension to the grazing industry. This is unfortunate as the ratio helps producers better understand how a paddock and everything in it functions.

A broader understanding of how carbon and nitrogen combine in the paddock would lead to better Reef protection. If management is not focused on maximising carbon flows into the paddock, to bind up nitrogen, then there is more chance of nitrogen getting on the loose and promoting algal growth on the Reef. Nitrogen on the loose is also a lead cause of soil acidification and nitrous oxide emissions. Besides the environmental consequences, it is money literally down the drain. 

It is the movement of carbon and nitrogen that is central to the profits of the grazing industry and this will be discussed further next week.

Next week's discussion: "Speeding up the faster moving carbon for increased profit and reduced methane"

Alan Lauder


ALAN LAUDER ON WHY CABON FLOWS? The different speeds of paddock carbon

Friday, November 10, 2017

Have you ever considered that all the different forms of carbon in a paddock are moving at different speeds?


Paddock carbon moves at different speeds depending on what type it is.

The first two columns drew attention to the difference between carbon flows and carbon stocks. It was explained why the success of rural producers relies on how well their management promotes the flow of carbon through their paddocks. Now I am going to add another level of refinement to this discussion of carbon flows in the paddock.

Given that all carbon in the paddock flows, some quickly and some slowly, maybe we should discuss carbon in terms of the speed of the flow, rather than simply stocks versus flows.

Some of the carbon that enters a paddock moves very quickly through the paddock on its way back to the atmosphere. Some stays a bit longer and some of the carbon is moving very slowly.

Different speeds = different functions

This suggestion of thinking speed of carbon may seem like a radical proposal, however it brings the discussion of land management back to exactly what all the different forms of carbon are doing. The faster moving carbon has a different role in production and landscape health to the slower moving carbon.

Short term resilience is linked to the faster moving carbon and long term resilience is linked to the slow moving carbon, as will be explained in a later column.

To understand the concept of different speeds of carbon, we have to go back to the idea of individual carbon atoms entering the paddock via photosynthesis then heading off in all different directions, before finding their way back to the atmosphere. Some quickly, some slowly.

Carbon atoms form different compounds as they keep moving. As you know, it is consumption of carbon compounds by life above and below ground that moves carbon around the paddock. Generally, the more times carbon is consumed, the slower it moves and the simpler carbon compounds become. 

Increasing the speed of faster moving carbon improves profit

There is a reason why a paddock is more productive when the faster moving carbon moves even faster. In the case of soil, everything that is joined to carbon, such as nutrients, becomes available to plants sooner if the carbon moves faster.

Apart from flowing through the landscape after entering plants, carbon also flows through sheep and cattle. Increasing the speed of carbon through these ruminant animals increases profits by getting them to market sooner and reduces the production of methane per kg of production. 

What speeds up the faster moving carbon will be discussed soon.

Carbon flows in the paddock involve virtually none of what we term long term carbon (the slow moving carbon). 

If you want to increase production in the short term, it is the faster moving carbon that increases production, not slow moving carbon. In the case of soil carbon, it is accepted in the scientific community that stocks of long term soil carbon are slow to change, which reinforces the point that long term carbon can’t to be responsible for short term increases in production.

Examples of different speeds of carbon movement

The carbon that leaves the paddock in the quickest time after entering is root exudates. Root exudates are carbon based compounds (sugars, amino acids and organic acids) released by the roots of plants. Soil microbes that are fed by root exudates procure nutrients that plants require. A good example of this process is microbes making phosphorus soluble and ready for plant use. This carbon leaves the paddock within hours of entering i.e. it is very fast moving carbon. Plants only release this liquid carbon into the soil when they are growing (photosynthesising).

Carbon above and below ground in plants is some of the faster moving carbon. However, the carbon in the stems will move slower than the carbon in leaves when it enters a cow or the soil.

The slowest moving carbon is soil humus and charcoal. It is virtually not moving at all.

Conclusion

Carbon is the organiser as it flows through the paddock.

It is the faster moving carbon that runs down quickly and needs constant replacement. Ground cover is a good example.

Carbon trading is more interested in the slow moving stable carbon, while the decisions rural producers make relate directly to the faster moving short term carbon.

Next week’s discussion: “How carbon and nitrogen work to together”

Alan Lauder



ALAN LAUDER ON WHY CARBON FLOWS? Why paddock carbon needs ongoing replacement

Wednesday, November 01, 2017

Did you know that after carbon enters the paddock, it is consumption that allows it to move and, in the process, change from one form to another? During each consumption event, some of the carbon will leave the paddock and return to the atmosphere, hence the need for ongoing replacement. Carbon usually leaves as carbon dioxide (CO2), however some leaves in the form of methane (CH4).


Paddocks become bare quicker if the focus is not on 'maximising' flows from any rain that falls.

Carbon consumption usually involves living things, however fire also consumes carbon compounds such as those in grass. In the case of fire, a lot of carbon leaves in a hurry. While fire is sometimes necessary as part of managing paddocks, it must be remembered that the carbon in burnt grass is not given the opportunity to drive production and soil health by moving through the above and below ground food chain.

When pasture management is discussed with producers, carbon is usually just associated with the soil. However, it is important to think of ground cover in terms of being carbon. When a paddock goes from having a good cover of grass, to bare, this is a reflection that all the carbon that was in the grass (45% by volume) has gone somewhere else. Some of the carbon that was in the grass would now be in the bodies of livestock, some in soil life including microbes, some in organic matter and the rest back up in the atmosphere.

With the mind set of carbon always moving, comes the awareness that carbon levels in the paddock will run down if you do not allow replacement carbon to keep coming in.

One example of how carbon keeps leaving the paddock


The above diagram representing the decomposition of plant residues highlights that it is critical to keep introducing new carbon into a paddock because carbon keeps leaving the system. The arrows on the CO2 sections represent the loss of introduced carbon via consumption i.e. oxidisation. The oxidisation process involves one life form consuming another and releasing CO2 in the process. As discussed, consumption by living things is not the only way carbon moves. Fire also consumes carbon by oxidising it. As we all know, remove the oxygen and the fire goes out. 

The diagram highlights that the outcome of photosynthesis is being reversed with every consumption event. You can see that some of the original carbon that arrived as short term carbon is now heading towards longer term carbon as it becomes less and less digestible. This is represented by the horizontal red bar becoming shorter.

The above diagram of what happens in the soil is a similar process to what happens in the rumin (first stomach) of sheep and cattle, where the gut microbes consume the grass that livestock have eaten. The sheep and cattle then consume the gut microbes as their food source and breathe out CO2 in the process. In the rumin, hydrogen is produced as part of the digestive process and microbes, known as methanogens, convert it to methane (CH4), which sheep and cattle burp out of their mouth. What the microbes do not consume becomes manure that then flows through the soil life.

As a general comment, 75-80% of carbon that enters the soil will be gone within twelve months. The actual amount consumed is determined by soil moisture and soil temperature as these two parameters determine how active soil microbes are.

Everything discussed here highlights that if your management is not focused on maximising the introduction of new carbon when the opportunities present after rain, then you run the risk of running short of this commodity, especially above ground.

Next week’s discussion: “The different speeds of paddock carbon”

Alan Lauder


ALAN LAUDER ON WHY CARBON FLOWS? Why we make the decisions we do

Wednesday, October 25, 2017

It is natural that the way somebody sees the world, influences the decisions they make. So, achieving change comes down to helping people see the world differently. We all want to help producers increase profits so we have to concentrate on changing how they see their paddocks by broadening their knowledge base.


My journey of seeing things differently

When I started as a producer in the 1970’s, I saw sheep and cattle as my source of income. That’s what I sold. 

Then I decided that the pasture they ate was the source of my income. I decided the sheep and cattle were really factories and the better the inputs (pasture), the more productive my living factories would be.

Then I decided that the soil was my source of income as that is where the pasture grew and the performance of the pastures was set by how well the soil let in water, stored it and how fertile it was.

Finally, I realised that flowing carbon was the source of my income. It is flowing carbon that feeds soil life necessary for improved soil structure and fertility. Also, cattle are 18% carbon and pasture is 45% carbon which further links flowing carbon to income.  After focusing on flowing carbon, I came to understand that the quality of the pasture is better with higher carbon flows over time because the carbon:nitrogen ratio of the pasture is better.

Thinking at another level

Discussing carbon flows is a different way for graziers to look at the landscape and understand how it functions. The paddock with the highest flows will be the most productive and more resilient, therefore producers need to operate with a new paradigm, a different function in their brain. They have to be able to imagine what is happening on a multitude of levels and time frames. At the moment, most producers can see only the outcomes, but don’t understand how they occur. They need to be able to visualise the processes they can’t see happening.  

Think carbon flows and you will see paddocks differently

With carbon flows, once you visualise the flows, you see the dynamics of the whole system and how it functions.

When producers get their head around the flows way of thinking, they focus on management that will maximise flows. This will be discussed in a later column.

Extension has explained the concept of carbon stocks to producers and why they are a resource to the business. However this is not the full story. I quote what Will Robinson wrote in a recent email, “I have got my head around the Carbon Flow rather than the Carbon Bank! It makes it so much easier!”

During a presentation attended by top management of Queensland DAF in October 2014, Stephen Martin documented his increased production by changing management after seeing his paddocks differently. He concluded with the comment, “The light bulb moment for me was visualising the flow of carbon through the landscape.”

Producers have no control over how much rain arrives but they do have control over the level of carbon flows generated by what rain does arrive.

Alan Lauder

Next week’s discussion: “Why paddock carbon needs ongoing replacement”.


ALAN LAUDER ON WHY CARBON FLOWS? Plant energy reserves are built by carbon flows

Wednesday, October 18, 2017

This perennial grass plant is struggling to come out of dormancy after good rain. The reason is because it is short of stored energy. The dead plants around it probably looked like this before they died. This is a landscape and a business that is in trouble because the role of flowing carbon is not understood.

Energy is stored in carbon compounds. Perennial plants run down carbon as they fire back up after rain then become carbon positive as they become established.

In the first column it was discussed how all life can’t exist without energy. The fifth column explained how carbon flows carry energy for all life to call on.

The energy story from a plant’s perspective

At the end of dry times, perennial grasses are dry old butts that have no green leaves to promote

photosynthesis. Yet they grow with the arrival of rain, so obviously they have a mechanism to start

growth after rain. We know that plant growth requires energy, so it is obvious that they must be

sourcing energy from somewhere.

It is the roots that hold reserves of plant carbohydrates (starches/energy) needed to stimulate growth when suitable growing conditions arrive. Some reserves are also held in the crown of perennial grasses. Apart from instigating growth after dormancy, these root reserves are also important for maintaining the plant’s tissue during drought, when photosynthesis is not occurring.

When perennial grasses have enough leaf area, they become self-sufficient in energy through

photosynthesis, and no longer rely on the energy supplied by the roots. With more growth, they start putting energy back into storage in the roots. When animals maintain leaf biomass at a low volume after rain, the root reserves used for initial growth are not replenished. If this happens on a regular basis then the energy reserves will eventually be depleted.

Plants have to eat too

Photosynthesis is plants sitting down to a meal. If we try to maintain our body function without

eating, we become anorexic. Any living thing that keeps drawing on energy reserves, without eating,

eventually dies. As a living thing, plants are no different. Root reserves should be thought of as reserve food, like the fat in our body. The horror images that come from Africa of emaciated people are no different to degraded pastures, in terms of the root cause.

Running energy reserves down in a plant is like letting a car battery go flat. The car won’t start.

Because perennial grasses produce less foliage from rain as they become unhealthy, this increases the grazing pressure on the rest of the plants in the pasture. The flow-on effect is that the health of the other plants will also drop, and so the pasture continues to decline at an increasing rate, all else being equal. Unhealthy plants are also more likely to suffer insect attacks and are also more susceptible to disease.

Energy reserves in plants are short term carbon brought in by carbon flows


Next week's discussion: Why we make the decisions we do

Alan Lauder



ALAN LAUDER ON WHY CARBON FLOWS? Think carbon before nitrogen

Wednesday, October 11, 2017

What is the one thing you can’t afford to run out of? The answer is carbon. Look at the cartoon and you will see that only the right hand side of the fence has carbon available for livestock to consume.


A person running a grazing operation can afford to supplement nitrogen (protein) when it is in short supply. However, it is not commercial to supplement carbon when it is short. Hay is expensive.

A bare paddock has no carbon while a paddock of frosted or rank grass has carbon but little nitrogen.

It is often stated that nitrogen (protein) is the limiting factor. However, this is only true when you are assessing what has grown.

Correctly manage carbon flows from the atmosphere to your paddock and you will still have options when it has  not rained for a while.  

It has been suggested that with average pastures, removing animals for three to eight weeks after rain increases pasture production by 50-80%. Given pasture is 45% carbon on a dry basis, this is a lot of extra carbon coming into the paddock for future use.    

For anyone who doubts the importance of allowing plants to grow after rain and build up the supply of carbon, try feeding lick blocks to sheep or cattle in a totally bare paddock.

How much carbon is in your pasture?

Getting back to basics, carbon is the main building block of grass and everything else that grows in a pasture, so the reality is that nitrogen will not be present if carbon is not present.

With grasses, there are approximately 20 to 25 parts of carbon for every part of nitrogen.

The ratio will vary depending on the species of grass, the stage of growth, or whether there has been a frost.

With wheat/oats stubble, the ratio is 90 to 160 parts of carbon to each part of nitrogen.

When grass is analysed to assess feed value, the figure for nitrogen is multiplied by 6.25 to arrive at the protein level. The first thing to understand about pasture plants is that carbon remains fairly constant from one plant to the next or between leaves and stems.

It is the nitrogen content that varies.

After a frost, it is the nitrogen, not the carbon that is lost.

The atmosphere is 0.03 percent carbon dioxide and 78 percent nitrogen.

However, this is reversed when we look at pastures, with carbon being the main component.


Alan Lauder


A healthy landscape