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? Methane is the carbon atom taking a detour

Thursday, March 22, 2018

The methane debate is one of subtleties, with the true issue being the production of methane per kg of production.

We have to go back to the start to understand where methane fits in. Carbon atoms come down from the atmosphere into the paddock and then head off in all different directions. Some find their way back to the atmosphere quickly and some slowly. One path of the carbon atoms is into sheep and cattle.

After carbon flows into a cow to keep it functioning, some will end up part of the cow (18%), some will leave as carbon dioxide, some will leave as manure and some will leave as methane.

At any point in time, a percentage of the flowing carbon in a paddock will be returning to the atmosphere. Think of methane as part of this exit process.     

In the atmosphere, methane has to be converted back to carbon dioxide, before the carbon atom is ready to come down into the paddock again via plants.

Methane has a bad reputation because it is a greenhouse gas. However, when it is created in a cow, it represents energy lost. Energy that the cow had in its rumen (first stomach) that was not utilised for growth. Reinforcing the energy aspect of methane, it is a hydrocarbon gas that is the principal component of natural gas.

How methane breaks down in the atmosphere

The atmosphere is continuously producing what are known as hydroxyl radicals (OH). These OH radicals only last a very short period of time because when they come into contact with a methane molecule, they react with it to form carbon dioxide and water vapour. 

Methane is a short term gas. It lasts in the atmosphere for 8.7 – 12 years, depending on who you talk to.

There are a lot of feedback loops in natural systems that try to maintain stability. My understanding is that if the atmosphere warms, then methane will break down quicker.

How ruminant animals (sheep, cattle & goats) produce methane  

Ruminant animals produce a lot of hydrogen during digestion, which is removed by organisms called methanogens. They do this by combining the hydrogen with carbon dioxide to produce water and methane.

The rumen (first stomach), is a very complex internal ecosystem containing millions of micro-organisms that break down what the cow eats. It is a bit like a fermenting vat. Fermentation of plant material by these organisms allows ruminants to convert lower quality feed to energy more efficiently than monogastrics such as humans, birds and pigs.

The cow is relying on these micro-organisms to keep reproducing, and breaking down what it has eaten. It is when the micro-organisms reproduce slowly and empty the rumen slowly, that we have a problem with both livestock production and methane production.

Methane is lost energy for animal production

It has been known for many years that methane production represents poor conversion of pasture to energy and, as such, is a waste gas.

Put another way, if you increase the efficiency with which an animal digests its feed, you reduce the amount of energy released by the rumen micro-organisms in the form of methane gas, and instead the energy is channelled into growth.

Methane emissions and feed digestibility

“There is a relationship between methane emissions and feed digestibility; therefore, modifying the feed intake for digestibility will reduce methane emissions” (Dr Roger Hegarty).

Reducing methane relies on what the ruminant eats moving faster through the rumen. The speed of passage is determined by the carbon:nitrogen (C:N) ratio of the diet. In other words, the C:N ratio determines the digestibility of the feed.

It is lower nitrogen levels that cause the slower passage. Like all forms of life, rumen microbes rely on carbon as the main building block of their bodies, but they also have to source nitrogen, before they can break down what has been eaten. If there is not enough protein (nitrogen) in an animal’s diet, then the microbes reproduce slower. If the rumen microbes multiply slower, then the flow rate in the rumen is reduced. An earlier column linked increasing the “speed” of carbon to increased production, i.e. increasing the speed of carbon in the soil and in the ruminant increases profits.

When discussing pastures, some people think protein and some think nitrogen. To determine the protein content of pastures, just multiply measured nitrogen by 6.25.

A leaf has a higher nitrogen content than a stem, which is why it is more digestible.

Methane emissions per kilogram of production

Differences between production systems become clearer when the outputs are expressed as the amount of methane produced per kilogram of production. The faster the passage, the less methane produced per kg of production.

Lower quality diets actually produce less methane per day, because less is happening in the rumen, but this is not the point. Animals on low quality diets produce more methane in total by the time they get to the meatworks. This is because it takes them longer to achieve the same level of production. The key to reducing total methane of slaughter animals is getting them to the meatworks quicker.

During drought is when methane emissions per kilogram of production are at their highest. This is when fodder trees and saltbush plantations can supply a protein source to improve the digestibility of the total diet.

To reduce methane production from breeders, graziers need to achieve higher reproduction rates, i.e. fewer breeders for the same natural increase.

Linking methane emissions to profit

Putting the methane issue into commercial perspective, it has been suggested that a 1% increase in production through a superior diet results in a 1% reduction in methane. The difference in methane production between grazing systems can be substantial. The level of methane produced is another example of the general principle that the greenhouse outcomes of agriculture are a reflection of economic efficiency.


What you, as a producer, make available for the sheep and cattle to eat determines the amount of methane they produce. This is why good management of carbon flows after rain is so important to increase digestibility of the pasture.

The major strategy for reducing methane production will be the same as the key driver for profitability in grazing: reducing the number of grazing days per kilo of product.

The key to reducing methane production is to reduce the time feed spends in the rumen with the methogenic bugs. A diet with a high C:N ratio will spend longer in the rumen and generate more methane than a diet with adequate protein.

It is improving the digestibility of the diet that is the cornerstone of reducing methane produced per kg of production.

Next week’s discussion:   “The Carbon Grazing principle relates to management of carbon flows”

Alan Lauder

ALAN LAUDER ON WHY CARBON FLOWS Small changes can make a big difference

Friday, March 16, 2018

Discussing management of carbon flows relates to both economic outcomes and environmental outcomes. This week is all about economics.

If I asked an average sheep or cattle producer if they could double their profit, I would be laughed at. However, if I asked could you increase production by 9%, I would get a hearing. The interesting thing is that they are both the same thing in a marginal industry. Why is this so? The table below explains why.

How a 9% increase in production doubles profit in a marginal industry.

To pick convenient figures, say it costs $10 to run an animal. If the animal produces $11 of production, then the profit per animal is $1. However, if the animal produces $12 of production, then the profit per animal is $2, i.e. a doubling of profit. BUT, going from $11 of production to $12 of production is a 9% increase in production.

What happens at the margins can be so important 

Now, an example of where some of the extra 9% can come from with better management of carbon flows to produce better pastures.

If your pasture management has a cow or ewe at 99% of required body weight for conception, you do not get 0.99 of a calf or lamb, you get nothing. A slight improvement in this area can make a big difference to the bottom line.

Improving genetics relies on more than the bull & the ram

Genetic gain is another area where some of the extra 9% of production can come from with better pasture management. 

I ran both cattle and sheep and, while the following discussion relates to sheep, the same logic applies to cattle.

I remember an old stud breeder telling me that people place too much importance on the ram, because each ram is put with 50 ewes. He said that at the end of the day, every mating involves one ewe with one ram. He said that if the ewes are not classed/culled, then the improvement due to a good ram is undone every time he meets a genetically poor ewe. He said it is the average of the ewes that determines how much good a ram can do. This is why I concentrated on achieving high lambing percentages, to ensure all the inferior ewes were removed.

The figures that follow are based on limiting breeders (sheep) to four age groups, i.e. keeping the breeders young. First time breeders have about 20% fewer lambs, and this naturally makes it harder to maintain a young flock when they are a high percentage of the total.

With a reproduction/lambing rate of 56%, this just maintains the breeding flock without any inferior animals being removed.  At 60% it is possible to remove 6.7% of inferior animals, i.e. a 4% increase allows 6.7% to be culled. With 70% it is possible to remove 20%. At 80% it is possible to remove 30% which provides good genetic gain while at the same time still keeping the flock young. If there are 5,000 breeding ewes, then a 60% lambing rate provides 100 young cull/reject ewes for sale, while a 80% lambing rate provides 600 cull ewes for sale. 

There is a big variation in production from the best animals to the worst. One year I sold the wool off the top 10% of the replacement ewes separately. This exercise was carried out prior to them being put with the rams for the first time. The wool they produced sold for 30% more than the other replacement ewes. The bottom third (based on quality) were not part of the exercise because they had been sold. You can imagine the difference between the elite ones and the bottom third that drag the average down.

Better genetics and improved constitution go hand in hand. It is improved constitution that drives increased production. Think of animals with a better constitution as being more resilient.

Animals lacking resilience when combined with pastures lacking resilience, is a recipe for low production. Higher carbon flows lead to more productive and resilient pastures which in turn lead to the higher reproduction rates necessary for genetic gain.

Another aspect that drives higher production, especially in the case of sheep where wool is being produced as well as lambs, is keeping breeders young. Youthfulness is very important for production in dry years when older breeders struggle to support offspring.

The 9% can come down to pastures lasting just a bit longer

It is in the marginal rainfall years, when you are desperate for some feed to stay in production, that the good managers really come to the fore. The better managers have fewer forced sales in the period just prior to rain, maybe say three times versus ten times for the average producer over time.

This aspect of increased production is simple mathematics, the longer the pastures last for, the fewer times you are forced to sell, with the resultant financial loss.

As a producer, I experienced this concept. One time the sheep were in the yards to be trucked the next day and it rained that night. Three years later, it rained three days before sheep were to be trucked. This highlights that the financial gain of pastures holding on just a bit longer, to stop forced decisions, is not academic. On each occasion, considerable money was involved: another example of the 9% increase. 

The 9% can be in different pasture response to rain

At one level, it is true that rainfall sets the level of pasture over time, including when it will run out and animals have to be sold or removed. However, the volume of pasture produced and time frames for forced sales, with identical rain, vary from one producer to the next.

How well grass responds to rain depends on how well carbon flows have been managed in the past. Long term carrying capacity (production) is set by the health/resilience of paddocks which in turn is set by carbon flows. The 9% will often reside in this area alone.

Producers growing up steers can run more with better pasture response and they are also ready for sale sooner.

A perennial grass, lacking energy reserves, is hardly responding to rain.

The plant above is lacking resilience because of poor management of carbon flows over time. This is an extreme example to make a point. When coming off a low base of poor pastures, a 9% increase in production is very easy to achieve. Simply do some short term resting of pastures after rain to increase carbon flows.


A lot can happen at the margins in both the natural world and the financial world. Go a little bit more into debt and you get sold up.

Better management of carbon flows is a major component of genetic gain, one of the key ingredients of a profitable operation.

Energy, nutrients and water all follow the path of carbon. So, any increase in carbon flows increases the availability of these three factors of production.

Why purchase an expensive bull and then feed the progeny to 80% of their genetic potential.

Next week’s discussion: “Methane is the carbon atom taking a detour”

Alan Lauder

ALAN LAUDER ON WHY CARBON FLOWS? Why short term removal of animals after rain rests all plants

Saturday, March 10, 2018

Plants are not all thinking the same in terms of their end goal with pasture rest. However, the one thing they all have in common is the need to bring in plenty of carbon. What animals chose to eat and when, has to be considered when implementing resting programs.

While perennial plants initially concentrate on growing new leaves after rain, they are very focused on using incoming carbon to replenish their energy reserves and build an extensive root system. This ensures they are always in the position to produce leaves above ground for carbon collection. For annuals, the goal is to bring in plenty of carbon quickly to complete their growth cycle and produce enough seed for the next generation. Naturally, perennials need to produce seed over time, but it is a lower priority. The annuals are opportunists who take advantage of short term favourable conditions, while perennials are in for the long haul.

Now an important point in relation to short term removal of animals resting all plants: not all of the necessary carbon will actually come in during the rest period, but it will come in as a result of animals being removed for about four weeks.

The mechanics behind animal & pasture interaction

The crux of what follows is that unless animals choose to consume it, a specific plant is being rested even if animals are on the pasture. SO, understanding how animals select their diet is critical to resting pastures successfully.

The table below explaining plant characteristics gives an insight into animal plant interaction over time. Most producers will not have the third group, the perennial edible shrubs like old man saltbush in their pastures, but they have to be included in this discussion for those who have this third tier of carbon collection.

Table: The different plant types and their characteristics

The plant groups are listed in order of decreasing palatability. In the same order, their growth cycle gets slower. The annuals are the most palatable and grow the fastest. At the other extreme, the perennial edible shrubs grow the slowest and are the least palatable.

Animals select to maximise their protein/nitrogen intake, i.e. they select plants or plant parts that have the lowest carbon:nitrogen ratio. They are going to select annuals first, then perennial grasses and finally perennial edible shrubs. Natural systems have evolved to ensure shrub protein is saved for dry times.

What happens with a single fall of rain

If good rain is a single fall, then the annuals will usually not establish during the four weeks following, and the most palatable feed on the return of the livestock will be the perennial grasses.

Four weeks’ rest, assuming they are resilient, will see perennial grasses reach the threshold of critical mass required, then they can easily stay in front of animal consumption and continue to build bulk.

If rain germinates annuals

In regard to timing, pasture rest starts when plants start to grow, not the day after rain. This little extra time means the annuals, the first choice of animals, are growing quickly by the time the animals return.

Animals set out to consume a given volume of plants, not a certain number of plants. The more the most palatable annuals have bulked up, the more they remove grazing pressure off each other when domestic animals are returned to the pastures.

Also, it has to be remembered that livestock do not consume all the plants the first day they are re-introduced to pastures. Therefore, even for the most palatable plants, the actual rest time will always be longer than the exclusion time of animals. This gives the annuals a chance to set some seed.

Because the animals seek out the annuals on their return, this takes a lot of grazing pressure off the perennials and gives them more time to complete their cycle.

When animals return, if either the more palatable annuals or perennial grasses are available, then the least palatable, the perennial edible shrubs like saltbush get extended rest. They are free to grow for a considerable time, even although the livestock are on the pastures. They need this extended time to leaf up as they are slow growers.

What happens if pastures are not rested after rain

At opening rains, perennial grasses respond the quickest, and their succulent shoots are readily eaten by stock, as they are available before the germinating annuals.

30 mm (1.2 inches) of rain producing different outcomes. Source: Pat Francis

When animals are not removed after rain, the landscape suffers on two counts. The animals can over consume the fresh new shoots which the perennial grasses produce by drawing on energy reserves. We have all witnessed animals chase green pick. If these new shoots keep getting completely removed, then the perennial grasses have to keep calling on energy reserves to keep producing them. As well, animals pull the more favoured annuals out of the ground before they have time to develop secure roots. Oats is an annual plant, and croppers never move livestock onto these crops as soon as they germinate. They let the crop develop roots and build bulk before it is used.

Implementing tactical rest after rain enhances the chances of germinating perennial grasses becoming established. This is because the animals will select the annuals in preference to the perennial seedlings.

A practical example

In January 1995, when there was perfect germinating rain, I succeeded in re-establishing perennial grasses from seed by removing the stock for only 4 weeks. On their return, the animals, in this case sheep, focused on the annuals and even ignored the perennial seedlings around the watering points. Only mature animals were returned as they had perfected their selection process and were less likely to select the perennial seedlings over the annuals. At the end of the exercise, the annuals dropped plenty of seed.

Encouraging animal selection

When plants have had sufficient rest to protect their future, allowing animals to select the most productive plants available is not an issue. Animals need to be allowed to perform to their genetic potential. Exposing ruminant animals (sheep & cattle) to the highest quality diet possible, increases their growth rate and reduces methane produced per kg of production. Because about 4 weeks rest spells all plant groups (the first two groups for most producers), the animals can start with the most palatable and consume the plants in order of preference as the season deteriorates. Having leftover bulk of some of the inferior grasses as the season deteriorates, then becomes low quality gut fill to go with supplements, or the protein supplied by edible shrubs.


The only way to spell a particular plant while animals are on the pasture, is to have more palatable plants available for the animals to choose.

If a plant is on the menu of animals, then it is protected by how many mates it has and how big they are.

If all the plants in a pasture have limited growth, then animals can maintain ongoing pressure on the entire pasture.

The required rest period after rain is determined by pasture resilience, because the level of resilience determines pasture response to rain. Also, the warmer it is, the faster pastures grow.

In a perfect world, pastures would be rested after every rain event. In a practical sense, they need to be rested enough to maintain resilience.

Next week’s discussion:   “Small changes can make a big difference”

Alan Lauder

ALAN LAUDER ON WHY CARBON FLOWS? Techniques for pasture spelling

Wednesday, February 28, 2018

Graziers often say they cannot rest pastures because the property is fully stocked. While this is true in one sense, we have to ask the question: Does the potential for resting and regeneration actually exist in our present pastures? The answer is usually yes, as I discovered while running a grazing operation.

If “rest” is seen as timing, as discussed in last week’s column, then the animals only have to be off the pastures for a short period of time, which can usually be managed. It is when “rest” is thought of as time that it is impossible to achieve without destocking.

The practical question is of course, where do you put your animals while the pastures are resting after rain? Here are some options.

Fence to soil types

With most properties, there is usually one area of a paddock that has a lower quality soil type compared to the rest of the paddock. This area can be fenced off. Often the grasses on this soil type are inferior, but are more than adequate when green. In this way, the most productive country can be spelled by using the inferior country when it is at its most productive.

The substantial short term increase in ground cover of the best country, guarantees the inferior country can then be locked up and rested on the next rain event.

Naturally there needs to be a balance of how often the inferior soil type is used to rest the best soil type, as it is now being grazed at a higher rate after rain.

While on the land, I implemented this approach of fencing to soil type, then suddenly realised how much potential production had been foregone in the previous years. Over a period of four years, the production capacity of one paddock increased by 25%, because of the regeneration that occurred on the best soil. Satellite imagery documented the improvement in the best soil.

Double stocking

If a paddock is in good order, then double stock it for a short period following good rain to rest a degraded paddock. Alternatively, spread the stock of the paddock being rested, over a few paddocks that are in good condition. On the surface, double stocking after rain seems to go against everything proposed by this column. Occasional “short term” over stocking will not harm a healthy pasture. It is ongoing bad management that does the harm. On the other hand, with well-timed rests, resilience can be added to degraded country.

After a property starts to regenerate, the secret is to only increase the long term stocking rate by half the increased carrying capacity and use the excess capacity to increase resting of pastures.

Paired paddocks

Another version of double stocking is the pairing of paddocks which run equal numbers of stock. With good rain, all the stock go into one paddock for four weeks, then at the end of the rest period, are divided back up again between the two paddocks, according to available feed. With the next good rain, they all go into the other paddock. With this system, 50% of the property is rested every time there is good rain.

While a guest speaker at the AGM of a Landcare group, I was told that a local used this method and it worked. They said that his property was in much better condition than his neighbours who were using continuous grazing.

The subtly of this method is that each rest lifts a paddock to a higher level, so that next time it is double stocked, it is more resilient. Short term overstocking does not have a long term negative effect, provided the management leading up to the double stocking is correct.

Conceptually, think of two columns slowly getting higher over time. They go back down just a bit with each double stocking, but then reach a new high with the next rest.

Using old man saltbush plantations as a resting tool

This is an option for lower rainfall areas and works especially well with sheep. Leucaena supplies the same option for cattle producers in higher rainfall areas.

Because Old Man Saltbush (OMSB) is drought resistant and frost resistant, it provides somewhere to put animals at the end of dry spells, when good rain arrives. Of course OMSB can be used any time it rains, to allow pasture resting.

Back in 1996 I was funded to conduct an on-property research project to perfect the use of OMSB for resting pastures after rain. One point that came out of the project, was that it is important that the rows of OMSB are not planted too close, i.e. to avoid leaving the grass percentage too low.

The advantage of using OMSB as a resting tool is that only a small percentage of the property is needed to rest the whole property. The lower the average rainfall, the more this is so. It has been calculated that in lower rainfall country, only 2% of a property has to be planted to saltbush to enable the whole property to be rested for one month a year after rain. This can be just a case of having a saltbush plantation somewhere in each paddock. Because of its slow growth cycle and deep roots, OMSB continues to grow after the animals are removed, i.e. in preparation to be used again in eight months if there is a rain event.

A producer I visited in South Africa in the 1990’s, who used OMSB, had brilliant pastures.

Bare rooted OMSB seedlings can be produced cheaply on property. This is a 500,000 nursery.

Agisting on a short term basis

Most people would never think of trucking stock out when it rains. However, if trucking is a short distance, it is a sound long term investment in the resource base.

Lower stocking rates

Some people take the short term position to lower total stock numbers by say 10%. This means they are in the position to rest 10% of the property with every rainfall event. In dry times they are losing nothing, because the property would be fully stocked at 90%.

This approach is suited to degraded properties that have a lot of unrealised potential. After some regeneration, the paired paddocks approach would then become a more commercially practical approach.

Cell grazing

This is a method that has already been well covered in literature. Cell grazing is a high capital expenditure approach, while the other approaches discussed are low capital approaches.

With cell grazing, pasture is rested with every rainfall event because most cells do not have livestock in them.

A case study

It is currently dry at Gladstone where Stephen Martin has a cattle property. Yet he currently has two paddocks that have been empty since the last good rain in spring. Stephen is always thinking ahead and these paddocks have been set aside to spell other paddocks when it next rains. At the end of the last resting program, there was enough grass for all the cattle without using these two paddocks.

To put these two empty paddocks into perspective, in 2014 Stephen explained at a forum he spoke at, that he had increased the cattle numbers on his property by 46% over what the previous generation ran. Not only does he now run more cattle because his management has increased carbon flows, but the increased flows have also given him resting paddocks for when it next rains. His calving rates have also increased. He said, “The light bulb moment for me was visualising the flow of carbon through the landscape.”


Graziers have to be ready to capitalise on any rain event that will bring in carbon.

Next week’s discussion:   “How short term spelling rests all plants”

Alan Lauder


Tuesday, February 20, 2018

The question has to be asked, what are we really trying to achieve with pasture rest?

The answer: Achieving the flow of carbon to all the parts of the paddock that it needs to flow into, above and below ground. Animals will reduce the flow of carbon if not managed properly. 

Some see pasture rest as an exercise in growing more pasture for sheep and cattle to eat. While this is an important outcome, there is more to it than this.

What pasture rest sets out to achieve

There is an element of the present and the future with pasture rest.

The present is growing more feed for sheep and cattle to eat, remembering that pasture (ground cover) is 45% carbon. Creating ground cover also protects the soil and soil life in the short term.

The future is building paddock resilience. Paddock resilience relies on plant resilience and soil resilience. When paddocks are resilient, they have the capacity to produce to their maximum each time it rains, i.e. to generate max flows of carbon.

To remain resilient, plants need carbon flowing into them to maintain energy reserves and build extensive root systems, necessary for sourcing water and nutrients out of the soil.

Pasture rest is also about maintaining the health of the soil in which plants grow. To be productive, plants require a healthy soil that supplies them with water and nutrients. For the soil to remain healthy (resilient), plants need to be allowed to provide carbon compounds to feed all the soil life responsible for keeping the soil well structured and fertile.

Rainfall/moisture activates soil microbes as well as plants

If pasture rest is seen in terms of generating carbon flows, then we have to consider all the processes that contribute to generating flows.

It is so easy to give all the credit to plants for generating carbon flows and overlook the important role soil microbes play in helping plants grow (photosynthesise) after rain.

It is moisture that activates the soil microbes to consume organic matter and start the process of releasing the nutrients in organic matter into forms suitable for plant uptake.

I was told recently that the bulk of the action with soil microbes consuming organic matter occurs in the first 48 hours after rain. Another person conceptualised it for me by saying there is a puff of carbon coming out of the soil after rain, i.e. microbes are like us in that they release carbon dioxide as they consume carbon compounds.   

Growing plants support soil microbes directly by releasing energy directly to them through root exudates (liquid carbon). Plants also make soluble carbon available to mycorrhizal fungi which are located on their roots. This allows the fungi to extend out into the soil and source extra nutrients for the plants. This is a case of carbon bargained for nutrients.

It is after rain that soil microbes produce growth promotants for plants. Some of the activated soil microbes are also bringing in nitrogen from the atmosphere.

Livestock should be feeding on pastures’ excess growth, not the first flush after rain. Otherwise, they are hindering all the processes just discussed.

The logic behind why pasture rest is TIMING and not TIME

Hang in there “cell grazers”, what you stand for is not being challenged here.

Nature has designed the system so that water activates the flow of carbon into the landscape via photosynthesis.

The bulk of the carbon arrives from the atmosphere in the short period following rain.

Straight after rain is when plants and microbes are working together. This is the time when plants have most in their favour to grow and produce carbon flows.

Straight after rain is when plants and microbes are working together. This is the time when plants have most in their favour to grow and produce carbon flows. 

Nature does not have a predictable pattern. Stated simply, we must allow nature to transfer carbon from the atmosphere to the landscape according to its time frame. This is why pasture rest is TIMING, i.e. “strategic rest” after rain.

Basing resting decisions on a certain period of TIME is no guarantee that carbon will come into the paddock because there is no guarantee that it will rain.   

I first raised TIMING versus TIME in a report in 1998. It was included in a paper I wrote with CSIRO for the proceedings of the 1999 International Rangelands Congress. The title of my poster, judged the best, at the 2008 Australian Rangelands Conference was, “Is pasture rest time or timing?”

When is pasture rest achieved?

Pasture rest is long enough when enough carbon has flowed to all of the areas in the landscape, above and below ground, that it needs to. This explains why paddocks lacking resilience require a longer rest period. 

After talking to a cross section of scientists and producers, it would appear that the required rest period after rain is about 4-6 weeks, remembering that temperature influences plant growth.

Why some are thinking TIME

It may be a misunderstanding of the cell grazing concept that is responsible for some land managers taking the position that pasture rest is about time. Cell grazing is often referred to as “time controlled grazing”.

I asked one of Australia’s leading cell grazers if he had a problem with me saying pasture rest is timing and not time, given that he locks up his cells for 120 days on average, which is time. He said he did not. He said the bulk of the outcomes he achieved over the 120 days was achieved in the short period after rain. He made the point that most of the cells did not have livestock in them after rain, so produced maximum flows. He also commented that he could achieve full recovery in four weeks. 

Cell grazing is just one of many methods producers use to increase carbon flows.

TIME relates to consumption

It is important not to confuse management of flows with consumption of existing stocks.

Resting for set periods of time when it is not raining, is a consumption issue (maintaining ground cover), and should not be confused with strategic / tactical rest after rain. The exception is when a regeneration event has occurred and freshly germinated perennial seedlings need to be protected to allow them to establish.

How much ground cover is consumed is important, but it is the second decision a producer makes, not the first. What sets the level of ground cover in the first place is the amount of carbon a particular form of management allows to enter the paddock after rain.

Provided it is not excessive, grazing is beneficial as it removes rank pasture that can inhibit pasture growth next time it rains.

Commercial practicalities of seeing pasture rest as TIMING

The practical aspect of seeing pasture rest as a short, but strategic, period of time, is that an alternative home for livestock only has to be found for a short time.

If pasture rest is seen as time, then animals have to be sold or agisted.


The people who achieve the most in land regeneration are not the ones who lock up country for the longest time. Instead, it is the ones who act when something can be achieved.

A rest at the right time is the basic catalyst for maintaining paddock resilience.

The only time you can prepare for drought is when it rains.

Next week’s discussion:   “Techniques for pasture spelling”

Alan Lauder

ALAN LAUDER ON WHY CARBON FLOWS? The two different processes plants use to generate carbon flows

Thursday, February 15, 2018

Did you know that there are two different systems of photosynthesis used by plants? One is called the C3 pathway and the other is called the C4 pathway. The main difference between these two systems is the compounds used in turning carbon dioxide into starch and sugar.

Plants using the C3 pathway rely on the enzyme, rubisco, to fix carbon atoms from carbon dioxide in the air. The first stable product in this process is based on three carbon atoms, hence it’s called the C3 pathway. 

Plants using the C4 pathway use the enzyme, PEP carboxylase, to fix carbon from atmospheric carbon dioxide during photosynthesis. The first stable product of this process is a four carbon molecule, hence it’s called the C4 pathway.

The photosynthetic pathway that a plant uses will determine the conditions under which the plant will grow. The chart below is a guide to their likely requirements and performance under differing conditions.

The difference between the C3 and C4 photosynthetic pathways

The conditions each grows best under

Generally, C3 plants are more “temperate” plants, growing best in cool, moist conditions. They take up CO2 through open leaf pores or “stomates” and convert this to carbohydrates (leaves, stems, roots and seeds). In cool, moist conditions, this process is three times more efficient in C3s than in C4s. Unfortunately, for C3s, as the temperature increases, rubisco combines with oxygen instead of CO2. This wasteful process is called photorespiration. It produces photoglycolate, a useless product to the plant, and breaks down carbon compounds to release CO2. In warmer, drier conditions, C3 plants will photorespire more than they photosynthesize. In effect, they begin to die. In contrast to this, C4 plants hardly photorespire at all, even as the temperature rises.

C4 plants grow best in warmer, drier conditions. The C4 photosynthetic pathway needs more sunlight energy than the C3 pathway to convert CO2 to carbohydrates. In hot, dry climates, very low levels of photorespiration balance this higher energy requirement. Most of the CO2 absorbed by C4 plants is permanently converted to plant material in warmer conditions. But in cooler conditions, C3 plants are more efficient converters of water and CO2 to plant matter than C4 plants. In fact, below 15° C, many C4 species begin to hay off as the energy necessary for the C4 photosynthetic process becomes increasingly limited. C4 plants grow best when energy from sunlight is plentiful.

Some examples of C3 and C4 plants

C4 plants include the main grasses of the tropical savannahs, including black spear grass, kangaroo grass and golden beard grass, as well as crops like sugar cane, sorghum and corn. C3s crops include winter cereals, legumes, temperate pasture plants and all trees. C4 pasture plants are already more efficient than the C3s growing beside them and are thought not to gain as much from increased carbon dioxide levels in the atmosphere.

Quality versus quantity

The leaves of C3 plants are generally higher in nitrogen (protein) than those of C4 plants under the same conditions. This is because C3 plants have a higher concentration of rubisco (a protein) in their leaves. This explains why animals seek out C3 plants in preference to C4 plants putting them at more risk of being eaten out.

Annual grasses are C3s which is consistent with them being highly sought after by animals.

While C3 plants may produce higher quality feed, C4 plants nearly always produce more feed than C3 plants over a 12 month period. C4 plants are more water efficient, producing twice as much organic matter per litre of water to what C3 plants produce. A CSIRO scientist explained to me that on average, C4 plants require ¼ litre of water to produce 1 gram of pasture and C3 plants require ½ litre of water to produce 1 gram of pasture.

When paddocks degrade, the soil has a lower nutrient level. This reduces their ability to supply the nutrient requirements of C3 plants.

Complexity increases carbon flows

The key thing a farmer or grazier wants to achieve, is to create an ecosystem that harvests carbon/energy efficiently. This requires multiple options to capture carbon. Having both perennials and annuals and C3 and C4 plants, where climate allows, is the best option. Almost all “natural” systems configure themselves to do this, but human intervention disrupts this process. We always seem to want to simplify the system by reducing the number of pathways, and thus the total efficiency of the system. 


Diverse grasslands are more capable of supplying ongoing “green feed” because they make the most efficient use of water and nitrogen when it is available. They are also more successful at maintaining the health of the landscape and making it more profitable, because carbon is being introduced and cycled more often.

If the climate changes, as predicted, then this will change the balance between C3s and C4s in some pastoral regions.

While C3 plants are seen in a better light because of their higher nitrogen content, we should never lose sight of the fact that C4 plants can photosynthesise at higher temperatures, when the C3s shut down and achieve nothing. It is better to have inferior carbon compounds, that can be supplemented for livestock performance, than having no carbon in the paddock for livestock to consume.

There is a need for more emphasis on how different these two plant groups are in their manipulation of carbon.

Next week’s discussion: “Is pasture rest TIME or TIMING?”

Alan Lauder

ALAN LAUDER ON WHY CARBON FLOWS? Plants don't just sit there and take it

Thursday, February 08, 2018

Plants may not be able to move around but that doesn’t mean they have no control over their destiny. They have an amazing array of strategies for surviving and improving their environment.

We need a feed and a drink and so do plants. Apart from the carbon in the atmosphere being a food source for them, plants get the other things they need from the soil.

Plants are the ultimate networkers. They send chemical instructions via root exudates to soil microbes, to get them to do what they need done. 

Root exudates: what they are & what they do

Not all the carbon from photosynthesis is used in the construction of leaves, stems and new roots. Some is released as organic substances by the roots of plants. The energy is released by plant roots in the form of root exudates. This energy is released to the organisms living on or near their roots while plants are growing (photosynthesising). Because of the direct energy contribution from plants, the population of microbes in the rhizosphere around root tips can be 5-50 times greater than in the rest of the soil.

Root exudates are a direct energy transfer from plants to soil microbes, while organic matter is an indirect transfer.

The complexity of plant interactions with soil microbes

Carolyn Ditchfield generously wrote this for me some years ago. This explanation by Carolyn explains everything much better than I could do.

“Perhaps not consciously, there is a pervasive impression that plants are at the mercy of their environment. This is reinforced by conventional agricultural practices that focus on feeding the plant and protecting them with various chemical concoctions.

It is true that plants are not mobile so cannot physically escape their location, but they have an amazing array of strategies for surviving and even manipulating their environment. 

Often overlooked is their ability to modify the root zone. Up to 30% of the photosynthetic energy accumulated by a plant is dumped into the root zone as sugars, proteins and carbohydrates. Apart from the fact that combined, all these exudates contain carbon, they also act as a food source for soil biology. 

Much like the food web above ground, different soil microbes respond to different food sources below ground, i.e. different exudates attract/stimulate different microbial populations; and these soil microbes are a remarkably powerful workforce with individual species able to solubilise minerals (plant nutrients), fight ‘disease’, fix nitrogen, decompose organic materials, restructure soils, hold water, etc. 

Maybe coincidently, different plants produce different exudates. But even more interesting, individual plants change the composition of their exudates with environment, season, climate or phase of growth.

Although the research is yet to formalise the link, the clues are accumulating. A plant’s ‘decision’ to release a particular type of exudate from its roots has an active effect on which microbes get ‘nurtured’ in the root zone, and hence an active influence over its own maintenance and survival.”

Some figures put on plant decision making

Research has shown that P-stressed lupin plants secrete about 20- fold more acid phosphatases from roots compared to P-sufficient plants.

The graph below shows the percentage of photosynthesis that cropping plants allocated to exudates (liquid carbon) depending on the abundance of labile carbon (short term carbon) in the soil. Perennial grasses display similar behaviour.

Source: Ken Sharpe

Mis-manage carbon flows and livestock get less of future incoming carbon


It is well known that plants allocate more carbon from photosynthesis below ground when soils are less fertile. This means less of the production from photosynthesis becomes ground cover for sheep and cattle to eat. All else being equal, soil fertility reduces if carbon flows into the paddock reduce.

Below is a paddock where plants are now allocating plenty of carbon above ground.

This is an area where plants have been allowed to improve their own environment. This photo was taken in the Traprock country in South East Queensland which is known for its low fertility. 


As soil organic carbon gets lower, plants must exude more liquid carbon from their roots to grow.

Root exudates from grasses are the fastest moving/flowing carbon. This carbon will be back up in the atmosphere within 24 hours of entering the plant.

If the top half of a plant is hardly photosynthesising because of poor animal management, then the roots will be exuding little energy to the soil microbes.

Shortage of plant available phosphorus is known to be a production issue in some pastures. The availability of phosphorus to plants is influenced by how much soluble carbon plants are able to release to soil microbes.

Alan Lauder

Next week’s discussion:   “The two different processes plants use to create carbon flows”

ALAN LAUDER ON WHY CARBON FLOWS? What really is paddock resilience

Friday, February 02, 2018

The traditional definition of resilience is a paddock that is functional and able to withstand adverse conditions.

For those seeking tangible evidence of when resilience exists, it is the ability of a paddock to generate carbon flows from rain i.e. how well the pasture responds to rain. Perhaps the best test of resilience is the ability of paddocks to respond to isolated small falls of rain during a dry period.

A paddock that has the capacity to successfully produce carbon flows is one that is also well equipped to better withstand extreme events, be they drought, heat or heavy rain.   

Linking resilience to different paddock responses to rain 

The fence line comparison above is a good starting point for discussing what underpins resilience.

The right hand side of the fence is a grazing paddock, not a farming paddock. Look at the surface water right up to the fence and nothing on the other side. This outcome is more than just different soil structure, as will be discussed.

Add some slope and the right hand side of the fence is at risk to erosion.

These two pictures show the productive capacity of each side of the fence at a later date i.e. the paddock’s inherent ability to produce carbon flows. The top photo is the left hand side of the fence and the bottom one the right hand side of the fence. The resilience of each side of the fence is very different. Stating the obvious, resilience and water use efficiency go hand in hand.

The two components of paddock resilience

Paddock resilience has two components, plant resilience and soil resilience, and both rely on carbon flows.

Plant resilience

Maintaining plant resilience relies on good animal management. Animal management that does not let plants grow to their potential after rain, reduces the flow of carbon into them.

Allowing carbon to flow into plants increases their resilience by increasing internal energy reserves for them to call upon and increases their root volume. 

The perennial grass plant above is what a plant lacking resilience looks like. It is struggling to come out of dormancy after good rain because it is short of stored energy. Energy reserves in plants are short term carbon brought in by carbon flows. In perennial grasses they are stored in the roots and also in the crown. These reserves are the energy source prior to green leaves collecting energy. This plant is generating no carbon flows to feed soil life, which is responsible for restructuring the soil and making it more fertile.

It is also not going to produce any ground cover. Ground cover increases water use efficiency by reducing evaporation in two ways, lifting the wind off the soil and keeping the sun off the soil. 

Increasing carbon flows into plants produces a more extensive and deeper root system to allow them to source more water and nutrients i.e. become more resilient. Roots are 45% carbon.

Roots act as wicks to take water down through the soil profile, especially important with harder soils. The water travels down beside the roots. The pooling in the fence line photo was not just due to poor soil structure, it was also due to a lack of roots in the paddock.

Soil resilience

One aspect of soil resilience is how well water enters and how well the soil is able to retain moisture over time to promote plant growth.

Think of the soil as a construction site. If plants do not supply carbon compounds to all the life in the soil that are responsible for keeping it well structured and fertile, then they die.

Carbon flows into plants are the true source of soil organic matter which is about 58% carbon (short term carbon). Organic matter is the raw material for humus which is long term soil carbon. Humus is the undigested portions of organic matter.  

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

Humus changes the pH of the soil and so buffers against any toxic elements present. 

Humus is smaller than clay particles, which is why it has a higher water holding capacity than clay i.e. it has a higher surface area to volume than clay.

Organic matter changes the bulk density of soil, which adds to water storage capacity. It also stores nutrients ready for soil life to mineralise them into the inorganic form which is plant available.

Flowing short term carbon also feeds the soil biology responsible for creating macro-pores in the soil. Macro-pores enhance air and water movement. These macro-pores will still be there after this fast moving carbon is back up in the atmosphere.

For every 1% increase in organic carbon, to a depth of 30 cm (12 inches), the soil is able to store an extra 144,000 litres of water per hectare. This is in addition to the water holding capacity of the soil itself.

With poor management, plant resilience reduces first, then soil resilience reduces. This highlights that your animal management affects the soil, by affecting plants first.

Short and long term resilience

The fast moving short term carbon (plant energy reserves, root volume, organic matter and ground cover) supplies short term resilience. On the other hand, the slow moving long term carbon (humus) supplies long term resilience. It protects the long term survival of the system. Humus will slowly decline without good management of carbon flows.

Maintaining short term resilience helps maintain long term resilience.  

Long term carbon being lost from the paddock because of little short term carbon to help protect it.

Increasing the pathways for carbon inflow

Because resilience relies on carbon flows, there is a need to increase the pathways for carbon to enter the paddock i.e. increase the mix of plants to cover all circumstances.

A production system based on perennials is more resilient than one based on annuals, simply because perennials generate more carbon flows over time, especially in marginal years.

Feedback loop with carbon flows

The discussion to this point, highlights that current carbon flows are influenced by previous management of carbon flows. This is why water use efficiency over time is linked to management of carbon flows.

Just as money makes money, carbon also makes carbon i.e. carbon flows lead to more carbon flows.


Both plant resilience and soil resilience rely on carbon flows.  

With a resilient paddock, more water leaves the paddock via transpiration (creating carbon flows) instead of as run off or evaporation.

Resilient paddocks are more profitable and looking at the bigger picture, they supply better environmental outcomes for the rest of society.

The only time you can build paddock resilience is in the short period after rain.

Next week’s discussion:   “Plants don’t just sit there and take it”

Alan Lauder


Thursday, January 25, 2018

A few years ago, while traveling in rural Queensland, I met an interesting woman in the Blackall newsagency. During the course of conversation she commented, “The expensive dieting programs in the city are a total waste of money. All you have to do is keep your mouth shut and move”. This woman was a clear thinker who was focused on getting back to basics.

Likewise, producers who focus on good management of carbon flows, understand that this is one of the basics you have to get right. If you get the basics wrong, nothing else will fall into place the way they should.

Carbon flows are the most fundamental thing a producer has to get right?

Carbon is the main building block of cattle, grass and soil life and carries the energy that all three require.

Paddocks can’t function without carbon flows because carbon is the main building block of all life. Cattle are 18% carbon, grass is 45% carbon and soil life is carbon based. Also, carbon is the carrier of energy that all life requires.

Nutrients and water also follow the path carbon takes. The more carbon that flows through the paddock, the better the other cycles function.

Without the ongoing flow of carbon and all the different compounds it forms as it keeps moving, the landscape would become bare and lifeless.

More flow = More meat and grain

A producer’s day job is recycling carbon i.e. managing carbon flows. Producers set out to turn a portion of the carbon that is flowing through the paddock into saleable carbon products, like meat and grain. The more carbon that flows, the more cattle and grain are produced for sale. 

All else being equal, the grazing paddock that has the most carbon flowing through it will be the most productive and resilient.

Has extension focused on the wrong aspect of carbon when discussing decision making?

Talking about carbon stocks is to look at an outcome. Talking about carbon flows is to understand what caused the outcome. With carbon, the “management decisions” producers make relate to carbon flows.

Long-term soil carbon is important for paddock health. However, if you want to increase production in the short term, it is the faster moving short term carbon that increases production, not the slow moving long term 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.

For those interested in long-term soil carbon, this carbon has to start the journey as short-term carbon in the first phase of carbon flows i.e. when carbon enters plants from the atmosphere.

The carbon flows concept is different to discussing the carbon cycle diagram     

The carbon flows concept, discusses the role of carbon as it keeps moving through the paddock, above and below ground, including through livestock. The concept explains what carbon does as it moves and the processes it activates, before returning to the atmosphere. It highlights that carbon is the organiser as it flows through the landscape. It discusses the different speeds of carbon to help producers better understand the different roles of carbon.  

The carbon flows concept should not be confused with discussion of the carbon cycle diagram. The carbon cycle diagram is a one dimensional discussion. It goes no further than saying that carbon cycles. It simply discusses the different pools carbon moves between.   

The easiest way to grasp the carbon flows concept is to think of individual carbon atoms entering the paddock from the atmosphere via photosynthesis and then heading off in all different directions, before finding their way back to the atmosphere. Some quickly, some slowly.

The different speeds of paddock carbon

Short term carbon is the fast moving carbon and long term carbon is the slow moving carbon.

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.

Why carbon suddenly turned up in extension

For the thirty years that I was a grazier up until 2000, not once was the word carbon mentioned to me. CSIRO confirmed this to be true. Land management was never explained in terms of carbon management, or more specifically, management of carbon flows. Nobody suggested to me that my day job was recycling carbon. It was never explained to me that the meat and wool I sold were actually carbon compounds. Now carbon is being discussed in extension but not in its full context.

It was climate change policy that introduced the word carbon into extension. This explains why current extension is focused on carbon stocks and measurement. This is where funding is being directed, not carbon flows projects.

The reason carbon was originally left out of extension can be traced back to reductionist science. Reductionist science breaks up landscape function into separate processes and is sometimes referred to as putting information in silos. Those who take a reductionist science approach place a lower importance on carbon than those who take a systems approach.

How moving carbon carries energy

During photosynthesis, light energy from the sun is converted into chemical energy. The energy of the sun is stored in the new molecular structures that carbon forms.

The carbon hydrogen bonds in C6H12O6 (carbohydrates) contain more energy than the carbon oxygen bonds in CO2.

Think carbon before nitrogen

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

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.

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

Thinking with a new mindset

It is natural that the way somebody sees the world, influences the decisions they make. Discussing carbon flows is a different way for graziers to look at the landscape and understand how it functions. 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. 

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.

Increasing the speed of the faster moving carbon increases profit & reduces methane

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. 

How quickly carbon moves from one life form to the next, driving production and landscape health, depends on how much nitrogen is present with carbon.

This is why the carbon:nitrogen ratio (C:N ratio) is an important concept for producers to understand 

Leaves have a higher percentage of nitrogen to carbon than stems i.e. lower C:N ratio. This allows microbes in the soil and microbes in the rumen of cattle to multiply faster due to the higher availability of nitrogen. The faster microbes are able to multiply and consume their carbon based food, the quicker the faster moving carbon moves.  

There is a reason why a paddock is more productive when the faster moving carbon (short term carbon) moves even faster. In the case of soil, nutrients joined to carbon become plant available sooner if carbon moves faster. In the case of livestock, nutrients and energy joined to carbon becomes available to sheep and cattle 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.  

Financial analogy

To put fast and slow moving carbon into a commercial analogy, think cash flows versus capital.

Cash flows keep you in business, just like carbon flows keep you in business.

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 fast 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 of perennial grasses to come out of dormancy and grow after isolated small falls of rain, is especially important in dry years when getting something to grow is critical.

The slow moving long term carbon, like soil humus, should be seen as part of the capital of a farming business. It is essential for increasing the “storage” of water and plant available nutrients that would otherwise escape the paddock.


Carbon is the organiser as it flows through the paddock.

Carbon stocks are simply a reflection of how well carbon flows are managed.

The health of the Great Barrier Reef and waterways is dependent on good management of carbon flows.

Because of their deep roots, perennial edible shrubs like saltbush and leucaena transfer the use of rain further into the future i.e. they can generate carbon flows when it is not raining. They also hold onto their nitrogen (protein) longer, with saltbush not affected by frosts.

Next week’s discussion:   “What really is paddock resilience?”

Alan Lauder

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.


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.

A healthy landscape