Carbon increases create miracle soils: GRDC

They call them “suppressive” soils because they suppress disease in crops. Scientists are racing to find out why. But they know 2 things: 1.  Soil microbes are responsible for them. 2. Soil carbon increases are the key. And  “There are soils right across the country where the incidence or severity of disease is suppressed, even in the presence of the pathogen that causes it, a host plant and a favourable environment,”  says Associate Professor Pauline Mele, LaTrobe University and principal research scientist, Department of Primary Industries Victoria (DPI).

“These disease-suppressive soils have been found to develop under management practices that supply higher levels of carbon inputs for more than five consecutive years. The carbon from plant roots and crop residues is biologically available and provides an important food source for soil biota, ” says CSIRO’s Dr Gupta Vadakattu in GRDC’s GroundCover 96 Soil Biology Supplement.

Disease suppression is the result of increased species density among microbial communities in soils associated with increased carbon levels. We know that, when soil carbon levels are rising, biodiversity increases and this has the effect of increasing resilience (or disease resistance). “We know the effect is due to the presence of a diverse range of ‘good’ micro-organisms,” says Professor Mele.

Three facts Dr Mele mentioned provide further evidence that soil carbon is a key influence:

1. Balance in the microbial  community is critical: “upsetting the balance or sterilising the soil can cause the disease to strike with a vengeance”.

2. It is not soil type specific; it could therefore be a soil health agent – such as carbon – that is at work: “ we believe every soil has the potential to be suppressive”

3. It is a feature of soil heavily influenced by a farmer’s management practices: “it’s just a matter of working out what management techniques will encourage it.”

The fact that a microbial community is a natural system and such systems exhibit ‘emergent properties’ as they become more complex. It is not one variable at work. However, reductionist science tends to look for the single factor. However the Professor says, “At this stage, though, we’re still trying to identify exactly what organisms, or combination of organisms, are doing the work.”

 “HIGH rainfall zone (HRZ) grain growers stand to increase yields and save significant amounts of money on chemicals, if the secrets of suppressive soils can be unlocked,” reports The Land. Growers lose an estimated $250 million each year from root lesion nematodes alone. “Soil biology is tipped to be the ‘next big thing’ in terms of productivity gains and a five-year research program is currently being funded by the Grains Research and Development Corporation (GRDC) to address some of the knowledge gaps.” Having poured scorn on soil biology as “snake oil” and ‘witches brew’ for so long, the GRDC’s epiphany is welcome.

“The soil biological resource under our feet is seen as something of the ‘last frontier’ for the grains industry… We know it’s about competition for resources. If we create a habitat that favours one type of soil microbe, say through repeated use of the same management practice such as addition of fertiliser or sowing the same plant types, the community may end up with fewer types of biota present; thereby reducing the resilience of the system,” says Professor Mele.

The writing is on the wall for chemical companies. “Using biological suppression to reduce crop losses, without chemicals or with minimum chemical input, could improve the profitability of growers worldwide,” says the Professor.                                      

More information about the Soil Biology Initiative II is available at www.grdc.com.au/soilbiology. Research partners include the Victorian Department of Primary Industries (DPI Vic), Queensland Department of Agriculture, Fisheries and Forestries (DAFF), Department of Agriculture and Food WA (DAFWA), and CSIRO.  

The Earth's Not Flat and All Carbon Cycles

THE VAULT vs THE HOLDING BAY

There is a battle between the belief that only stable fractions of soil carbon can be traded and the belief that only Total Carbon is necessary. The outcome will determine whether agricultural soils can achieve the dramatic levels of “drawdown” of Atmospheric Greenhouse Gases claimed by those who believe soil carbon can be a “secure bridge to the future”.

The Fixed Molecule Theory Vs The Cycling Molecule Theory

The Fixed Molecule Theory: “Carbon is sequestered in soil when rendered immobile in the form of stable fractions such as humus. Carbon held temporarily in labile fractions cannot be said to be sequestered because it is oxidised in a short time.
“Therefore only carbon stored in soil as humus can be counted towards a farmer’s tradable tonneages of stored carbon.”
Such a restraint would reduce the incentive for landholders to revert and lose the benefits to society of the sequestration.

The Cycling Molecule Theory: Carbon by its nature cycles.
The Carbon Cycle is fundamental to life on Earth.
All forms of Carbon are cycling between sink and source.
These cycles vary in length of time, some very short, some very long, depending on the nature of the sink.
No sink is permanent.
All sinks act like ‘holding bays’ - some hold Carbon Molecules for centuries and some for seconds.

Climate Change is caused by imbalance in the cycles: ie. too much carbon is being held in the Atmosphere and not enough in other sinks. Carbon sequestration occurs when the Carbon Cycle is adjusted to delay its transition from one sink to another.
When Carbon is captured by Vegetation and becomes a component of soil it enters a ‘holding bay’.
Sequestration takes place when the amount Carbon in the holding bay increases and that increase is maintained.
The volume of Carbon in the holding bay is not affected by the rate of C atoms escaping so long as the rate of C atoms arriving remains equivalent or greater.
If the rate of arrivals is equal to the rate of departures, Carbon is said to be in a “steady state”.
If the rate of arrivals exceeds that of departures, Carbon is said to be sequestered.
If the rate of arrivals falls short of the rate of departures, Carbon is said to be emitted.
Therefore the key to sequestration in soil is not the individual molecule but the representative value of a molecule.
Increases in “Molecular Value” can be created by changing land management practices.
These changes can start with:
Ceasing to cause losses of Carbon from soil.
Ie., refraining from baring the soil by ploughing, burning, overgrazing.

Change Land Management
50% of Australia’s top soil has been lost in 200 years of conventional land management
75% of Organic Carbon has been lost at the same time
By changing to a neutral position - not emitting/not sequestering (steady state) - the land manager has made a positive contribution in ‘foregone emissions’.
The ‘holding bay’ contains more Carbon.

The Impact of Time
The act of changing land management has one impact on the holding bay.
The effect of time on the process has another impact.
Ie. Planned grazing uses the movement of animals to increase the efficiency of the conversion of sunlight into vegetation. The effect of even grazing, even distribution of dung, and the tilling effect of hooves in concentrated areas - combined with long recovery periods - is a gradual increase in fertility and biological activity until a tipping point is reached and vegetation and soil condition improve rapidly. These indicate increases in Carbon levels.

The Bucket Theory

The Bucket Theory of Soil Carbon Sequestration holds that Carbon levels can ONLY be increased by the addition of Organic Matter of the type known as ‘shoot dry matter’, ie. leaf litter. As such, the claim by leading Carbon Farmers to have increased their soil carbon from 2% to 4% in 10 years is technically impossible.
.This is incorrect. Increased Organic Matter does nurture micro-organisms which manufacture soil carbon. But there are at least three other ways to increase carbon in soils:
1. Microbial balancing;
2. Rhizodeposition; and
3. Phototrophism (or in-soil photosynthesis).


The amount of organic carbon in soil is a balance between the build-up which comes from inputs of new plant and animal material and the constant losses where the carbon is decomposed and the constituents separate to mineral nutrients and gases, or are washed or leached away. This theory limits the amount of carbon a soil can sequester to a theoretical ceiling of dry shoot biomass introduced into the soil.
Microbial communities are at their most effective when they are balanced. When one or several links in the chain are missing, the processes of decomposition and photosynthesis can never be fully effective. Just as a football team with several positions unmanned cannot hope to score. Inoculating soil with the missing members of the community is like putting players into empty positions. The effectiveness of the team is increased by an order of magnitude.

Rhizodeposition: For many plants as much as 30–50% of the C fixed in photosynthesis is initially translocated below-ground. It is estimated that the ratio of SOC derived from below-ground plant C to that derived from above-ground dry shoot was nearly 2:1 in long-term corn plots.*
In fact, corn may translocate more to the soil from below- than above-ground. And below-ground plant C is the major source for conversion into more stable forms of SOC.**
In soil photosynthesis: There is a class of microbial life called ‘autotrophic’ or ‘phototrophic’ that do not rely on Organic Matter for their sustenance. They use solar energy to grow via the process of photosynthesis. Cyanobacteria and Algae are examples.
These add Carbon independently of other processes. Autotrophic bacteria obtain their energy from sunlight (by photosynthesis) or the oxidation of ammonium, sulfur, and iron. They get their carbon from carbon dioxide.
• phototrophic cyanobacteria
• green sulfur-bacteria
• some purple bacteria
• many chemolithotrophic species, such as nitrifying or sulfur-oxidising bacteria.***
Many species of algae live in soils and photosynthesise their carbon as plants do.
Increased microbial activity automatically means increased methane emissions as the microbes die.
Increased microbial activity also means increased carbon production.
A landholder can manage their soil for microbes (ie. bacteria-dominance vs fungi-dominance).
The logic behind the Molecular Value Theory supports the contention that only Total Carbon is necessary or trading purposes.
Focus on fractions has several negative outcomes: It complicates the process of measurement. It makes measurement more expensive. It denies the landholder the right to sell sequestered carbon. It delays the commencement of trading and the benefits to society of biosequestration.
Total Carbon at Point In Time B MINUS Total Carbon at Point In Time A = Carbon Sequestered For Purpose of Trade.
Total Carbon is all that is needed for trade.

*John M. Baker,, Tyson E. Ochsner a,b, Rodney T. Venterea, Timothy J. Griffis, Tillage and soil carbon sequestration—What do we really know? Commentary, 2006 Christophe Nguyen, Rhizodeposition of organic C by plants: mechanisms and controls, Agronomie 23 (2003) 375-396
**Modeling the incorporation of corn (Zea mays L.) carbon from roots and rhizodeposition into soil organic matter
J.A.E. Molinaa, C.E. Clappb, D.R. Lindenb, R.R. Allmarasb, M.F. Layeseb, R.H. Dowdyb, H.H. Cheng Soil Biology & Biochemistry 33 (2001) 83–92
***Hellingwerf K, Crielaard W, Hoff W, Matthijs H, Mur L, van Rotterdam B (1994). "Photobiology of bacteria". Antonie Van Leeuwenhoek 65 (4): 33147. doi:10.1007/BF00872217. PMID 7832590.

Dark satanic windmills?

Several months ago we were informed that 300+ wind turbines were going to be erected on the hilltops surrounding our peaceful valley. We had heard it on the grapevine, although those neighbours who had been signed up had been sworn to secrecy. The company crept into our valley and  set neighbour against neighbour.  The good news is that we have heard that several prominent farmers have withdrawn from the deal and that could be the end of it. Wind 'farms' are great on desolate landscapes that make them look like art. But not where people are living their lives. How many wind farm executives live within eyeshot of a wind farm? None? And they wave the results of public opinion surveys that tell us 75% of people like the idea of wind farms. If it is true that there are 900 turbines planned for the stretch between Wellington and Mudgee, and that is repeated in other places, the percentage in favour may slip dramatically. Carbon farming in the shadow of these dark satanic (wind)mills is not Nature's way. PS. Please dont call them 'farms'.

100 Years: it's political, not scientific

Some believe that 100 years is the time it takes for a tonne of CO2 to cycle through the atmosphere. It is not. This is a common misconception. Eg., "The internationally accepted timeframe for ensuring sequestration is equivalent to emissions is 100 years. This is based on the estimated life of one tonne of carbon pollution in the atmosphere." - Carbon Farming Initiative Handbook. (P.17)

Let's ask a scientist:
john.friend@industry.nsw.gov.au wrote

"Regarding your questions about where did I get the "100 year" figure for carbon dioxide and its relation to the issue of permanence. The figure has its origins in the Kyoto protocol. The IPCC have then used 100 year horizon values to compare the other greenhouse gases to carbon dioxide (the IPCC table is here). Regarding a specific reference for the 100 year value, I can't find one. From what I can gather, the rationale behind using 100 years is from this paper which states an "adjustment time" of 50-200 years". This paper actually states that the decay of excess CO2 in the atmosphere cannot be expressed in a single figure, so the 100 year figure seems to be more politically correct than scientifically correct."

Dr John Friend, Leader, Soil and Salinity, Natural Resources Advisory Services, Department of Primary Industries, NSW Department of Trade and Investment, Regional Infrastructure and Services

“This 100 year timeframe is a policy-determination, not a technical one,” reveals a peer--reviewed report by Pedro Moura Costa and Charlie Wilson.(1) It is a period chosen by the IPCC for calculating the Global Warming Potential of each different Greenhouse Gas compared to CO2. For instance, Nitrous Oxide has a GWP of 298 (ie., one tonne of N2O is equivalent to 298 tonnes of CO2).

Some believe that 100 years is the time it takes for a tonne of CO2 to cycle through the atmosphere. It is not. This takes only 4 years, according to an IPCC Report. “The turnover time of CO2 in the atmosphere, measured as the ratio of the content to the fluxes through it, is about 4 years. This means that on average it takes only a few years before a CO2 molecule in the atmosphere is taken up by plants or dissolved in the ocean.” (2.) However, it can take far longer for the atmosphere to adjust to the new levels of CO2, up to 200 years. (3.)

The EcoSecurities analysts calculate that removing a tonne of CO2 and holding it for 55 years is sufficient to counteract its effect on Global Warming. The IPCC uses 20, 100 and 500 year periods in much of its analysis. “The Kyoto Protocol set the time horizon against which [GWPs] are to be determined at 100 years (addendum to the Protocol, Decision 2/CP.3, para. 3)." (4.)

"To be consistent, it can be implied therefore that the Protocol also requires the benefits of sequestration in counteracting the radiative forcing effects of CO2 emissions to be evaluated over a 100 year time horizon. Any uncertainties derive from both this choice of time horizon, as well as future scenarios of atmospheric CO2 concentrations, are not technically driven but rather are a natural consequence of ‘arbitrary’ policy selections.”

“Functional Permanence”

Clearly, there is no definition of Permanence for Biosequestration that is dictated by Scientific Fact. The periods quoted range from 4 years to ‘forever’, with points of 20, 50, 55, 100, 200 and 500 years in between. The choice of 100 Years appears to have been a function of the need to find a scale on which to compare the Global Warming Potential of various Greenhouse Gases. Its choice as a time horizon took place as part of the negotiations around the Kyoto Protocols and was based on functional considerations. One function – the engagement of farmers in soil carbon sequestration activities – was overlooked.

FOOTNOTES:
(1.) Pedro Moura Costa and Charlie Wilson, An equivalence factor between CO2 avoided emissions and sequestration – description and applications in forestry, Mitigation and Adaptation Strategies for Global Change, Volume 5, Number 1, 51-60
(2.) Watson, R.T., Rodhe, H., Oeschger, H. and Siegenthaler, U. 1990. Greenhouse gases and aerosols. In IPCC Report No 1, World Meteorological Organization and United Nations Environment Programme, Cambridge University Press.
(3.) “This short time scale must not be confused with the time it takes tor the atmospheric CO2 level to adjust to a new equilibrium if sources or sinks change This adjustment time… is of the order of 50 - 200 years, determined mainly by the slow exchange of carbon between surface waters and the deep ocean.” ibid
(4.) "Reaffirms that global warming potentials used by Parties should be those provided by the Intergovernmental Panel on Climate Change in its Second Assessment Report (“1995 IPCC GWP values”) based on the effects of the greenhouse gases over a 100-year time horizon, taking into account the inherent and complicated uncertainties involved in global warming potential estimates. In addition, for information purposes only, Parties may also use another time horizon, as provided in the Second Assessment Report.” IPCC, REPORT OF THE CONFERENCE OF THE PARTIES ON ITS THIRD SESSION, HELD AT KYOTO FROM 1 TO 11 DECEMBER 1997, PART TWO: ACTION TAKEN BY THE CONFERENCE OF THE PARTIES AT ITS THIRD SESSION, 25 March 1998, P. 31, Decision 2/CP.3

Why measure charcoal in soil?

There's charcoal running across the chart dead straight. It never changes. Why, then, do we measure it at all? It is said to be costly. It takes us no closer to a reliable baseline methodology. That's all we need for trade to commence. Soil Carbon Credits Now!

Soil Carbon baseline ALERT

Farmers involved in Action On The Ground projects which have soil carbon measurement as a key objective should ask their scientific adviser about the baseline measurement methodology you will be using. The requirement that the farm-scale or paddock-scale measurement method used for Action On The Ground be consistent with that used in the SCaRP is confusing. “SCaRP was not set up to baseline carbon contents on paddocks or farms”, Dr Jeff Baldock wrote in a paper published late last year.  So where does that leave you? Ask your scientific adviser the following questions:

1. Do we have a soil carbon baseline methodology that meets the Department's requirements?
2. Do we know if the baseline measurements that we take for this project will be useful for measuring carbon sequestered that we can put towards gaining offsets should they become available?
3. Will our involvement in this project disqualify us from earning soil carbon offsets in future because of the Additionality Integrity Standard? What can we do to avoid this outcome?

Now you can afford to increase soil carbon

One of the biggest puzzles about soil carbon has been solved. In 2008, 5 scientists published a short paper called "The Hidden Cost of Carbon Sequestration".* Many people thought it shot a big hole in any prospect of Soil Carbon trading. Effectively, it made the claim that a farmer could not afford to increase carbon levels in their soils because humus ties up nitrogen and other nutrients needed by plants to grow. The farmer would have to buy extra fertiliser to replace that stolen by the humus and it would cost more to do that than soil carbon trading would pay.  The lead author told me that, based on his paper's argument,  the increases in soil C achieved by leading carbon farmers were doubtful. "

I am aware of Colin Seis's remarkable achievements, and I have wondered 
how he has succeeded in increasing soil organic matter in the topsoil by
 2%. If that increase is largely humus, then it is likely to contain, in 
organically bound form, about 2 tonne/ha of N, 400 kg/ha of P and 300
kg/ha of S.  I puzzle about where such large amounts could have come
 from.

 Regards, 

John Passioura".  Well, now science has solved the puzzle. Free-living nitrogen-fixing bacteria are supplying 75% of the N a 2t/ha cereal wheat paddock in the Mallee uses, according to the Victorian DPI. A 12-year trial found bacteria are delivering 35kg/ha each year. In an intensive cropping regime the organic carbon level rose from 0.80% to 1% between 1997 and 2011. Cropping is usually a carbon-exporting activity. The CSIRO's Dr Margaret Roper has published a review of literature that estimates that the theoretical potential of the contribution of these bacteria is up to 150kgN/ha. The DPI's Ron Sonogan reported the Mallee trials: "Assuming a 0.2% increase in OC each year, this may well have added another 120kg/ha of nitrogen to the system over 14 years." The  widespread shift to no-till and stubble-retention over the last 20 years has increased the carbon inputs which are a key driver for bacterial N2 fixation. Estimates of fixation were set more than 20 years ago and are therefore in need of up-dating, say the scientists. Australian Farm Journal reported the findings earlier this year, proving that the nutrients incorporated in humus don't have to come out of a bag.

*GRDC Groundcover Magazine Issue 76, p.19  (2008)

Don't call it Carbon Farming

They destocked Henbury Station and they’ve locked all 500,000ha of it up, and called it Carbon Farming.  It is the most high-profile example of ‘carbon farming’ but it sends all the wrong messages. Call it “Conservation” or a National Park, but it is not farming. It is simplistic and wrong to say that locking country up will protect it from degradation. The relationship between animals and vegetation is symbiotic when managed for balance. Grazing animals need plants for food. Plants need animals to graze them to prevent loss of groundcover and desertification which occurs when grasses die and oxidise. Plants need animals to disturb the soils around them and incorporate their carbon-rich dung and nitrogen-rich urine into it. Grazing can reduce fuel loads, reducing the severity of wildfires. And grazing is the only way that we can produce food in the rangelands. But not just any old grazing. Balance must be achieved by exposing the plants to grazing only to the point where the plant can easily recover. The roots of the plant need the leaves to be trimmed because they die back and then they return downwards. In each direction - coming and going - the soil microbes are excited by the food that the roots give them. Decomposing roots are partyfood for bacteria, etc. Roots returning by pushing down through the soil release delicious nectar that is also partyfood. The more partyfood we can offer soil microbes, the more they will manufacture the soil carbon which builds fertility, soil stability, water efficiency, biodiversity, and resilience. Destocking is a tactical tool, but it is not a strategy. It is not the presence of animals that is the problem; it is the recovery time allowed to the plant to deploy its leaves for maximum growth and maximum extraction of carbon from the atmosphere through the unique action of photosynthesis.

Is there money in dairy manure methane destruction?

Dairy farmers are caught in a price war between the supermarkets on top of a long term decline in their terms of trade. The new methane destruction opportunity could give many of them a lifeline in the form of a new revenue stream from carbon markets. The economics of methane destruction will dictate its success. The cost to install a system has been variously quoted at anything between $80,000 and $300,000. Many dairy farmers won’t have the money lying around. But there are other questions that need answers: 1. Will the farmer qualify for offsets when they do install a system, and 2. How long into the future will these offsets be available? The uncertainty is caused by the notion of common practice. The Additionality Principle holds that if 5% of farmers in a location or market or environment adopt a practice, the practice is now likely to be taken up for its inherent benefits rather than the incentive of offsets. So the early adopters get offsets, but only until the practice reaches the 5%, after which it is declared common and offsets cease. Australia has around 7000 dairy farms. 75% of them currently use anaerobic ponds. Dairying is location specific. Farms tend to be clustered in districts where soils and rainfall are favourable. The principle of ‘common practice’ only works if the practice has inherent benefits for production or cost reduction. Now piggeries need energy to warm sow stalls, so they can save a lot of money on their electricity bills. Dairies are also big users of electricity. But will that be enough to encourage a farmer unlucky enough to be in the +5% cluster to stump up the cash? “They would have done it anyway” is at best a guess… and a most unscientific method on which to base a plan to save the planet.

Global Warming good for soil carbon traders

GOOD NEWS for farmers who choose to trade soil carbon offsets: Global Warming will increase soil carbon sequestration rates for decades ahead, according to a recent research results summarized by the Center for the Study of Carbon Dioxide and Global Change (CO2science.org). As the CO2 levels in the atmosphere increase, most plants increase photosynthetic rates to produce greater amounts of biomass. This leads to greater inputs of carbon to the soil from roots, root exudates and dead above-ground plant material. It’s not just about more biomass, either. CO2 enrichment typically reduces decomposition rates of dead plant materials present in soils.  This phenomenon often leads to greater soil carbon sequestration. Scientists have concluded that, in spite of predicted increases in temperature, this stimulation of the below-ground carbon sequestration could exert a negative feed-back on the current rise of the atmospheric CO2 concentration. Finally, with more carbon in soils, soil structure and fertility should be improved, providing a positive feedback that further enhances plant growth and soil carbon sequestration.