THE CARBON GRAZING PRINCIPLE RELATES TO MANAGING CARBON FLOWS

The principle has as its basis, that effective pasture rest is achieved when enough carbon has flowed above and below ground to all the areas it needs to. The level of carbon that flows through a paddock determines plant and soil resilience AND the amount of ground cover for livestock production. Likewise, environmental outcomes, such as water quality, rely on good management of carbon flows.

Dr. John Williams, former head of CSIRO Land and Water, launched “Carbon Grazing – The Missing Link” in November 2008

Carbon Grazing is a principle and just that, not a new land management system. It underpins all successful land management systems.

Carbon Grazing is not new science, it is a different focus. It is another way of looking at how a paddock and everything in it functions. It focuses management on when the bulk of the carbon flows into a paddock.

Think of plants as the entry point of carbon into the paddock. After entering plants, it then flows everywhere else in the paddock.

The bulk of the carbon that comes into a paddock arrives in the short period after rain.

Carbon Grazing relates to the first phase of carbon flows, which is the introduction phase,  i.e. when carbon moves from the atmosphere to the paddock via photosynthesis during plant growth.

This is when the level of carbon available to flow through the paddock above and below ground, including through sheep and cattle, is set.In a sense, the principle is an action plan.

Carbon Grazing is strategic (tactical) rest after rain, and is based on the premise that 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.

CARBON GRAZING APPLIED IN THE PADDOCK

Carbon Grazing is short-term removal of animals from pastures after rain.

Scientists I met in South Africa carried out research which suggested that with average pastures, removing animals for 3 – 8 weeks after rain, increased pasture production by 50 – 80%. Given pasture is about 45% carbon when dried, this gives an indication of the increased carbon flows, including below ground.

When people say they can’t afford to rest pastures, it begs the question, can you afford not to. 

Carbon Grazing is resting pastures for 4 – 6 weeks after rain.It is important to not get caught up on the exact time between four and six weeks, as factors like temperature influence the necessary time. Also, the length of rest required, depends on the resilience of the paddock, as resilience is at the centre of pasture response. In turn, paddock resilience relieson past management of carbon flows. One producer I spoke to, with really healthy pastures, is of the opinion that he can achieve full recovery after about four weeks.

The rest period does not commence until the plants actually start growing, which provides time to relocate animals after rain. 

IS PASTURE REST TIME OR TIMING?

There are some subtle realities that underpin the Carbon Grazing principle. Because there is no pattern to when rain arrives, in other words when carbon arrives, the message is that pasture rest is TIMING and not TIME. Basing resting decisions on a certain period of TIME, is no guarantee that carbon will arrive.  

The practical aspect of seeing pasture rest as TIMING, instead of TIME, is that you only need to find an alternative home for animals for a short period of time.

Some of the “increased” ground cover that results from a resting exercise, can be utilised as somewhere to put animals next time it rains, i.e. the capacity for resting resides in existing pastures. An earlier column discussed techniques for resting pastures after rain without selling animals.

Stating the obvious, continuous grazing never implements the Carbon Grazing phase of rest after rainfall.

Cell grazing is just one of many ways Carbon Grazing can be implemented. A well respected cell grazer commented to me that although he locks his cells up for 120 days on average, which is a TIME approach, he said the bulk of the outcomes he achieves, occurs in the first 28 days after rain. He said he implements Carbon Grazing, because when the rain arrives, the bulk of the cells do not have animals in them.

Carbon Grazing is not the same as wet season spelling (an Australian term) as some people mistakenly think. Wet season spelling involves a much longer rest period than Carbon Grazing. Also, wet season spelling increases grazing pressure on the remainder of the property for the wet season. This is because all the animals are pushed into a reduced area.

The box above is saying that animals should start harvesting what resides above ground after adequate carbon has flowed to all parts of the landscape, including below ground. This approach will ensure future animal production and ongoing resilience of the production base. It will also ensure better environmental outcomes.

CARBON GRAZING GIVES CONFIDENCE TO THE BROADER COMMUNITY

Producers who implement the Carbon Grazing procedure at least once a year are in the position to represent to the broader community that they are responsible custodians of the land.

The term “Carbon Grazing” was coined in 2001 and registered the same year. It was coined for the purpose of drawing attention to the importance of maximising carbon inflows for both profits and environmental outcomes. 

CONCLUSION

Carbon Grazing is about attending to the most fundamental thing a grazier has to get right, and that is to maximise carbon flows from any rain that arrives. If you do not attend to the basics, then nothing else will fall into place the way they should.

Carbon Grazing is not a new land management system. It is a general principle. 

Discussing carbon flows is the entry point for discussing what profitable and sustainable land management is, not carbon stocks. As important as carbon stocks are, they are simply an outcome of carbon flows.

Carbon is the organiser because energy, nutrients and water all follow the path of carbon.

For those wanting extra supporting detail, read the appendix that follows this short explanation of Carbon Grazing.


APPENDIX

The natural world can’t function without “carbon flows”. This is because carbon is the main building block of all life  on the planet and is responsible for supplying energy that all life relies on.

Without the ongoing flow of carbon and all the compounds it forms as it keeps moving, the landscape would become bare and lifeless.    Carbon is always moving, sometimes quickly, sometimes slowly. After entering the landscape via photosynthesis, one path of carbon involves moving along the two food chains, one above ground and the other below ground. This involves moving from one living thing to another living thing.

How successfully pastures are able to introduce carbon into the landscape is determined by animal management. Plants and animals have evolved together and rely on each other. However, if animals dominate plants, then carbon flows are reduced. In the absence of animals, pastures become moribund and again have a lower capacity to introduce carbon. 
All else being equal, the grazing paddock that has the most carbon flowing through it will be the most productive and resilient. 

THE TWO ASPECTS OF CARBON

“Carbon flows” and “carbon stocks” are related but different debates. Up until this point in time, the emphasis in extension has been on discussing carbon stocks and measurement, not carbon flows. See my earlier blog post dedicated to this topic

PUTTING CARBON FLOWS INTO PERSPECTIVE

Plants rely on carbon inflows to construct themselves. Roots, stems and leaves are about 45% carbon. It is plants that make carbon available to the two food chains that underpin commercial production and positive environmental outcomes.

Paddock resilience is critical for reducing the negative effects of extreme events, be they drought or flood
Paddock resilience has two components, plant resilience and soil resilience.

Allowing more carbon to flow into plants increases their resilience in two ways;

  • it increases internal energy reserves for plants to call on; and
  • it creates a more extensive root system to give plants access to more water and nutrients

Soils with more carbon flowing through them are more resilient because they have improved water infiltration, increased water holding capacity and are more fertile.
Long-term soil carbon is very important, however its existence over time has to be seen as an outcome of carbon flows and how well they are managed.    

Those who take a systems approach, place a high emphasis on carbon, while those who take a reductionist science approach see water as more important. The reality is that a grazing operation has no control over how much rain arrives, however, there is some control over how effective it is in producing carbon flows. How effective rain is depends on whether it enters the soil or ends up in gullies and, in the case of water that enters the soil, whether plants are healthy/resilient enough to fully utilise it. Both these issues are determined by management of carbon flows i.e. the level of carbon flowing into plants and then the soil over time. When we take a big picture approach (a systems approach), it quickly becomes obvious that better management of carbon flows increases water use efficiency.   

The best way to gauge how well we are managing carbon flows over time, is to observe the outcomes or lack of outcomes after rain. Past management of carbon flows does influence the level of current carbon inflows.

Because carbon is always moving, with some returning to the atmosphere on a regular basis, there is the need to keep bringing in new carbon
In the case of new carbon entering the soil, on average 80% will be gone in twelve months. The above ground exit of carbon can be even more extreme depending on livestock management or fire. 

In dry years, the potential for bringing in replacement carbon is much lower. This is the time when implementing Carbon Grazing is even more important for staying in business.

The faster moving short-term carbon provides short-term paddock resilience and the slow moving long-term carbon provides long-term resilience. Carbon Grazing has an immediate impact on short term resilience and contributes to long term resilience over time.

It is while grasses are growing after rain, that they 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 to utilise. 

For those interested in the trading aspect of soil carbon, the introduction phase of carbon flows only includes short term carbon. This highlights that long term soil carbon has to start the journey as short term carbon, in the first phase of carbon flows.  

When perennial pastures are emerging from dormancy, there is the potential for so much lost production if animals consume new shoots. 

One industry extension program in Australia discusses ground cover in terms of not consuming too much, which is important, but does not discuss land management in terms of increasing carbon flows to provide more ground cover. Deciding on the level of consumption of pastures is the second decision  producers need to make, with the first one being management of carbon flows  to increase ground cover prior to consumption. Over consuming carbon flows after they have arrived is very different to reducing the flow of carbon in the first place, and is by far the lesser of the two evils. Carbon flows end up above and below ground, while animal consumption only involves what ends up above ground.

When soils become less fertile because of poor management of carbon flows over time, plants allocate a higher percentage of the incoming carbon below ground. This means livestock have less to eat. This is another reason why poor land managers are at a bigger disadvantage during marginal years when rainfall is below normal.

USING DIFFERENT APPROACHES TO ENGAGE PRODUCERS

Discussing carbon flows is a different way for graziers to look at the landscape and understand how it functions. If extension discusses all the processes carbon becomes involved in as it flows through the landscape, then it quickly becomes clear to producers why the paddock with the highest flows will be the most productive and more resilient. Hence the advantage of implementing Carbon Grazing.

Producers need to operate with a new paradigm, a different mindset. They have to be able to imagine what is happening on a multitude of levels and time frames. At the moment, a lot of 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.

A rangelands scientist told me recently that producers like recipes, however his concern was that recipes are prone to fail if circumstances keep changing. He said, Carbon Grazing is not your normal recipe, it is a flexible recipe. It is instigated on the basis of one parameter  and requires only one action. This simplifies application.

The instruction left in the rain gauge to act and remove the animals from a paddock is random in timing. However, the instruction to act is always based on the same criteria, which is the presence of grass growing rain and, always requires the same action. The only variable is that the required rest period shortens as landscape resilience improves due to better management of carbon flows over time.

TIMING THE HARVEST OF CARBON FLOWS

When graziers let animals harvest carbon flows too early following rain, they interfere with the biophysical conduit (leaves) that are responsible for introducing carbon into the landscape.

In other words, graziers should only be letting animals harvest the surplus, not the means by which a usable surplus is generated. They should harvest what resides above ground after adequate carbon has flowed to all parts of the landscape, including below ground. This approach will ensure future animal production and ongoing resilience of the production base. It will also ensure better environmental outcomes, including better water quality in waterways.

CONCLUSION

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

Carbon Grazing is about maximising potential inflows of carbon. It is the window of opportunity too many people miss.

We can’t change how much rain falls, however we can change how much carbon flows into the paddock from what rain does fall.

Short-term improvements in paddock health and productivity are driven by the short-term carbon introduced in the first phase of carbon flows. Also, the carbon in long-term soil carbon has to start the journey as short-term carbon in the first phase of carbon flows.

The best way to gauge how well we are managing carbon flows over time is to observe the outcomes or lack of outcomes after rain.


ALAN LAUDER

METHANE IS THE CARBON ATOM TAKING A DETOUR

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.

CONCLUSION

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.


ALAN LAUDER

SMALL CHANGES CAN MAKE A BIG DIFFERENCE

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.

CONCLUSION

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.


ALAN LAUDER

WHY SHORT TERM REMOVAL OF ANIMALS AFTER RAIN RESTS ALL PLANTS

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.

CONCLUSION

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.


ALAN LAUDER