The CARBON STILL with its high accuracy
the TIGER TOOTH SIZING AUGER with its fast simple sample collection
the SEE-SAW SIEVES for quick ready to test sample preparation was all designed specifically to meet the high accuracy and consistency requirements of large financially institutions.
The Carbon Still above was selected to be part of a two months
exhibition on design held at Monash University, Melbourne
April -May 2019. Allan Yeomans with Gran-daughter Rhiannon.
This is a video made at the exhibition. It shows the CARBON STILL
It does not show the Sizing Auger
Australia, China and the United States are the only nations with huge agricultural land areas. If we want to stop global warming, we can’t without those countries using their agricultural soils to help clean the atmosphere of the CO2 excess.
The Yeomans Carbon Still and sample collection system, or something very much like it, is an absolute necessity if soil carbon sequestration is to happen sufficiently to halt Global Warming.
The Yeomans Carbon Still and soil sampling system, I believe is the only soil carbon test unit in the world that allows soil carbon sequestration to be very easily and accurately monitored by virtually anyone, and with soil sample sizes that are meaningful and not minuscule. It tests samples weighing up to 2 kilograms (over 4 lbs). It gives quick and accurate and consistent results. The Carbon Still is easy to use, easy to set up in a farm shed and requires only a power supply and access to a basic service station sized air compressor.
There are several systems that are used to determine changes in soil carbon, unfortunately, most involve some form of specialised chemical analysis and additionally, in all these procedures, the actual samples are extremely small. They’re under and 5 grams but most only cater for samples weighing one gram maximum. These systems were originally designed for detailed soil chemical analysis under laboratory conditions. For minerals not humus. None were for soil carbon sequestration. When they were designed (some in the 1930s) the carbon content, and specifically the organic matter content were generally only of very minor interest.
It is hard to believe and accept that such tiny samples could give accurate representations of the carbon content of, possibly a 100 ha or 1,000 ha paddock, or even a 10 ha paddock. A few grams is ludicrously small: it’s just not enough for financial institutions to trust. In Australia the Department of the Environment seems to have abandoned the concept of actually testing for changes in levels of organic carbon sequester. (Except for one methodology of the Department’s own design, relating to grazing lands, which seems to have received no significant or meaningful support from Australia’s 157,000 farmers.) So the Department have decided to allocate credits to a farmer if he alters his management systems on any area of land in some way stipulated by officers of the Department.
What do we really need to know?
We must not forget that the only objective being considered must be the removal of carbon dioxide from the air to combat Global Warming. Nothing else matches this importance. So, what we really need to know, and all we need to know is; “has the farmer been successful in removing carbon dioxide from the air by increasing the carbon content of his or her soil.” This increase can only come as an increase in reasonably stable organic carbon. And that’s humus. If it’s not yet humus, if it’s still decomposing and still being consumed by such things as earth worms and soil bacteria then it’s nonsense to include it as soil organic carbon. As much as 90% of such material, we can expect to be lost to the atmosphere in a matter of weeks. And therefore most test systems, quite sensibly, screen such material out when ever possible.
Our job is to weigh it and then pay the farmers for their efforts to produce genuine, stable humus.
In the Yeomans Carbon Still a sample being tested is often as much as two thousand times the size used in all other systems. And apart from screening soil samples to pass through the universally accepted 2 mm screen aperture. There is no other sample preparation required.
Reality demands that soils can be tested easily, cheaply and accurately. Reality demands that field samples be taken. Reality demands that samples are taken that are of a sensible and practical size and in turn are easy to weigh with high accuracy. We therefore built a unit and a system to test individual samples with sample sizes as big as two kilograms – kilograms not grams – and definitely easy to weigh. Weighing accuracy of the Carbon Still comes out at around 1.5 grams in a 2,000 gram sample. That’s 0.075%. So we allow 0.1%.
Most soil carbon testing protocols use chemical analysis techniques which unfortunately give differing results for different soil types. All also only handle tiny samples. To ask financial bodies to put their trust and money in such testing systems is absolutely ludicrous. Coming into increasing favour now, in soil carbon analysis, is the Loss On Ignition (LOI) procedure. Sample sizes are, by necessity for the equipment used, tiny: 10 grams being the biggest ever used. In a LOI test the prepared sample is oven dried with oven temperatures slightly in excess of 100°C The sample is then placed in a desecrater to keep it dry. Then quickly weighed. The sample is then placed in an oven with temperature set at a predicated temperature to oxidise the organic carbon compounds. The surrounding air in the oven oxidises the organic carbon into carbon dioxide and carbon monoxide. Predicated temperatures vary, usually generally irrationally and range between 325° C and 550° C.
From research information and experience we maintain that temperatures approaching 350° C are too inconsistent. With forced heated air flow, as in the Yeomans Carbon Still, temperatures around 400° C are ideal.
The recent EU Standards nominate 525° C to 575° C. in muffle furnace type ovens which are relying on ambient air to oxidize. (See Note 2 among others, this Note refers to EU standard TC WI :2003 (E) for Loss On Ignition testing for sludge, soil and bio-waste is 550°C + or – 25°C.) In existing systems a considerable amount of time is required to bring the soil samples up to the nominated temperature range in the test. This is unavoidable as the oven temperature range has to be relatively narrow for consistency. Maximum oven temperatures must not exceed the higher temperature nominated in the relevant protocol so the soaking of heat into the centre of even a small sample is time consuming. These soaking times are always hours and can often be days.
Testing for Soil Organic Carbon with the Yeomans Carbon Still and its Allied Equipment
In the Yeomans Carbon Still, air at the relevant nominated temperature is forced through the test sample. Heating is therefore almost immediate and temperatures are consistent and controllable. In the Carbon Still sample sizes are around 1.5 to kilograms, and with single tray use 400 grams to 600 grams gives accurate and consistent results. Drying times are usually around 30 minutes, including “soak” times. The Loss On Ignition procedure is generally less than 90 minutes. These short times are more than sufficient. It’s the benifit of using our unique forced air process.
There is a 100 mm (4inch) diameter vertical tubular inner oven within the Carbon Still. The sample is constrained and held in place to effectively block air flow around the sample. Air at the nominated temperature is therefore forced down through the sample. For drying, air temperatures are set a little over 100°C. When air temperatures exiting the lower oven rise to exceed 100°C, drying can be confidently deemed complete,. For assurance, once the exit air temperature first exceeds 100°C it should be held there for 15 minutes after which the sample and its inner oven container can be weighed.
Throughout the drying and high temperature cooking process, the test sample remains in its tubular inner oven container. This container, with the sample, is weighed as a single unit. After determining a dry weight reading, high temperature air is then forced through the test sample to produce ignition. Air flow rates and air input temperatures are manually adjusted to control ignition rates and temperatures.
With the surface area principle we propose, stones and rocks in the samples can simply be discarded. They need only be brushed a little, to remove any attached fine soil material.
However: when a soil density based calculation system is used it’s obviously necessary that stones and rocks cannot be discarded. Stones and rocks are a meaningful factor in accurately determining average, soil density. Therefore all stones and rocks in the samples must stay in the samples, and must in turn be ground up sufficiently to pass through a 2 mm screen.
This is not necessary when using the surface area principle. (If a density system is a set requirement of the relevant Authority then this can be accommodated with the this same equipment. The Sizing Auger System takes the TIGER TOOTH SOIL PIPE and the auger down to a known and pre-selected depth. The sample is dried and weighed and knowing the volume of the used section of the sleeve, the dry density is then easily calculated.)
In the Carbon Still the central tubular oven containing the test sample is mounted in a “see saw” arrangement. Weighings are determined by balancing the “see saw”. The see saw is initially balanced, approximately, with a couple of heavy weights. Final and accurate balancing is achieved by simply adding water to a beaker or laboratory measuring cylinder placed adjacent to the weights in the balance tray. A pipette is ideal for this weight adjusting procedure. After the drying process, and again after the cooking process, some number of millilitres of water are removed from the beaker to balance, and every millilitre is one gram.
It’s simple, easy and very accurate. After the cooking process the sample is cooled using forced cool air so that exhaust air temperatures always slightly exceed 100°C. Condensation cannot occur. So desiccators are not required at all in this system. The cubic centimetres of water removed after drying, and the water removed after cooking tells us the original water content of the sample and the weight LOI in grams. Some soils are formed from geological material that when heated to the temperatures called for in LOI soil testing release small quantities of water of crystallization (magmatic water). Some release carbon dioxide. This obviously effects the LOI weight loss determinations. However we are not interested in absolute figures, we only want to know what changes have occurred over the previous year. Organic matter content will change but the geological nature of the soil will not. Hence the LOI attributed to the geological base of the soil is irrelevant in soil carbon sequestration calculations. It is also suggested that as the organic matter increases in the soil in a test hole the proportion of geological material must conversely decrease. In monitory calculations this is a slight detriment to the farmer. In consequence, it just cannot in anyway lead to some possible overpayment to a farmer for his success in his efforts to terminate Global Warming and catastrophic Climate Change.
SIZING AUGER comprising the TIGER TOOTH SOIL PIPE & SCREW AUGER for Infield Soil Sample Collection Soil collection procedures and organic matter calculations can be based on the surface area of the sample and the paddock, or it can be a density related calculation. When density related, organic matter is determined and recorded as a weight percentage or in grams per kilogram. Often samples are called for at various stratifications in the soil profile. The reality is that combating Global Warming is the whole point of soil carbon sequestration and measurement. Soil samples have to be taken. And those samples have to be measured cheaply, efficiently and with definitive and financially acceptable accuracy.
We have to remove from our atmosphere that trillion tonnes of excess carbon dioxide that we have dumped there over the last 75 years. No esoteric academic niceties nor luxuries can be permitted to interfere with that essential and absolute requirement.
Another pedantic and wasteful procedure is for authorities to demand to know, and therefore have determined at what the depth, in the soil profile, the new organic carbon is formed, and whether there is more or less at some specific depth, and whether it might vary over time. It’s a wasteful and extravagant and pointless exercise. It’s another delaying tactic for those industries and countries who have a callous need for global warming to continue unabated.
The surface area concept is considerably cheaper, more logical and delightfully practical. If we have sufficient test sites, and we know the surface area of those sites and the depth the farmer expects to fertility enhance their soil, we have all we need to know. And we can pay them. And we all win.
A reliable and workable reward based system for soil sequestration demands easy, reliable and accurate sample collection and collation. This obvious and necessary requirement demanded that practical and suitable equipment had to be designed and developed to suit all locations and all soil types. So we developed the SOIL PIPE concept where, in principle, an auger is screwed into the ground as is common but, in our SOIL PIPE system the auger is enclosed in a metal tube with a known specific outside diameter. In operations, as the auger penetrates the soil the surrounding Tiger Tooth Sizing Pipe follows the auger bit down. The top of the tube is reinforced and may be hammered down to follow the bit. In practise however, the tube almost falls down the hole and simply follows the bit down. A very precisely sized sample is always obtained, quickly and easily.
Nothing else with reliable accuracy seems to exist and be used anywhere in the world. Unenclosed post hole diggers, tree planting augers and general garden tools, all of unspecified, arbitrary and widely varying designs are invariable recommended. Reproducible and trustworthy results were therefore, at best, improbable. With our TIGER TOOTH SIZING PIPE no soil is able to fall into the hole from the sides. This usually happens with no pipe surround because of the softness or dryness of the soil being drilled. With the SOIL PIPE, even in hard soil, loose soil, or even sand, the sample size and bulk, being strategically confined by the SIZING PIPE remains precise and consistent.
Our SIZING TUBE has an outer diameter of 115 mm (standard light wall 4 inch pipe). In operation the PIPE penetrates down to half a metre into the soil; or less if desired. The Sleeve lengths can, for special operations, be made longer.
There are two systems for collecting the soil from the auger. In one the SOIL PIPE fits through a hold in a one and a half metre square Collection Blanket laid on the ground. All the soil from the hole, and only the soil from the hole is ultimately collected on the Blanket. Consistency is assured. This soil is then collected together on the blanket and poured into a suitable container for transport.
In the second system a 10 kg soil sample can be collected and dumped in a bucket on the vehicle usually in way under 5 minutes. It’s a fast operation. In this second sample collection system, a fabric collection cone hangs under the auger and collects the soil as the auger digs. It looks like an inverted parachute. So we call it “The Parachute System”.
Tiger Tooth Sizing Auger – ready to dig
There is therefore no necessity to clear the surrounding area of grass or loose vegetation as when using the ground blanket system. The auger, the sampling pipe and the collection cone is a one piece item. It incorporates the auger, the collection pipe and a fabric collection cone.
The unit is best mounted on a small flat trayed utility vehicle equipped with a small electric winch. The auger system is never removed from the winch. The winch control, itself mounted on the assembly, allows the auger to be lowered into the ground and when full of soil can be hoisted onto the vehicle or over a bucket for emptying. If the auger is tight in the ground it can be easily removed using the lifting winch.
There is a small 4 inch diameter 2 stroke power auger supplied with these soil collecting systems. The spinning auger consistently breaks up any hard soil ready for screening and lifts the soil to the top of the SOIL PIPE where it is discharged. With the ground blanket system a fabric material Mini Skirt, confines the discharge so the soil is all collected on the blanket and can then be swept up and shovelled into a suitable container.
With the Parachute Collector the complete field rig is lifted with its crane and swung over the hole site.
With the Parachute Collector It generally takes less than a minute to obtain a complete, half metre depth, sample. The outer diameter of the TIGER TOOTH SIZING PIPE equates to a calculated ground area. This area consequently bears a known mathematic relation to the paddock area. In turn the organic carbon content of the blended and screened, heated and tested sample mathematically determines the organic carbon content of the paddock, down to the nominated sampling depth.
It should be appreciated that as the fertility increases due to changed farm practises, soil density will slightly decrease. In monitory calculations, (just as was considered with water of crystallization) this is a slight detriment to the farmer. In consequence, it just cannot in anyway lead to some possible overpayment to a farmer for his success in his efforts to terminate Global Warming and catastrophic Climate Change.
SEE-SAW SIEVES for Sample Cleaning, Screening and Preparation .
The field samples from the particular paddock can generally be placed directly into the See-Saw Sieves having already been broken up into small pieces by the auger.
Sometimes, if the soil is wet or damp it can clump together into balls. If this happens the combined field samples are best spread on a clean floor and allowed to air dry for a few hours and then remixed. They are best air dried to the point where the material can be obviously and comfortably worked through the See-Saw Sieves supplied with the Carbon Still Kit.
Direct sunlight should be avoided in the drying process. The material should then be thoroughly mixed to form a homogeneous composite. The composite is then worked through the See-Saw Sieves.
The set of sieves nest together and when the soil has been worked through any sieve, leaving only the stones and rocks, the sieve is tilted up and the rocks discharge onto the ground or into a bucket. See photo.
That sieve is then lifted off and the soil is worked through the next finer sieve down. The final sieve has a 2 mm aperture and below that is a tray where the sample material is ultimately collected. Sliding heavy block, (a still block with scraper is supplied with the unit) or a house brick, back and forth over the material gives quick and efficient screening.
There are three sieves mounted on each other with a collecting tray under. The top one has approximately 10 mm openings. The next approximately 5 mm openings. The lower sieve is a standard 2 mm opening sieve. Generally using either a Loss On Ignition procedure or a procedure based on chemical analysis, the biggest of the particles in the material being tested is required to pass through a 2 mm aperture metal screen. I believe this is a sane and sensible requirement and it is in generally use in most laboratories worldwide.
There are three sieves plus the collector tray in the system. The support frame for the sieves also serves as a packaging frame. The photo shows the three sieves nestled inside an inverted support frame and held with a bungy cord. Thus transporting the system is easy.
The “pack” can stand up, or lay down on any side, or in any way required. The above shows two sieves and a Collecting Tray under them. Also the red part is a steel rubbing tool, to do the same job as a small house brick mentioned earlier. After the material has been worked through the top sieve this sieve is then tilted up to discharge any stones and rocks. (In other systems the rocks can’t be discarded,
Where soil density is involved in calculations, all stones and rocks have to be retained and ground down to fit through the final 2 mm sieve.
When one sieve has been used it is tipped up to discharge any stones of sticks or other similar materials. This upper sieve is then removed to gain access to the next sieve down. Any fibrous material such as plant roots and plant leaves must be hand selected and discarded in the screening process. Dead or decaying organic carbon material and soil humus from all the field samples is ultimately located in the lower collection tray.
This final well mixed material must be split, possible several times, until a sample weighing around 2 kilograms is obtained. The numerical subdividing of the combined bulk sample can be done by mechanical separation, by “splitting”, or simply by weight, until a suitable sample size suitable to “cook” in the Carbon Still is obtained.
Finally the Collecting Tray itself is emptied into a suitable container for mixing and splitting for testing in the Carbon Still. The final sample is then loaded into the Carbon Still for drying, and also to obtain a dry weight balance.
After a dry weight balance has been determined, the supply air is then brought up to the nominated LOI temperature until system exhaust temperatures stabilize. The system is held there for a “soak” period. Use 30 minutes after temperature stabilization is well established.
The soak period is to ensure that complete organic matter combustion is complete
Samples with high organic matter content require the monitoring of both input air volumes and temperatures. These are easily controllable in the Yeomans Carbon Still. This control is often necessary to prevent excess temperature rises resulting from the sometimes high heat release from the combustion of the sample’s own organic matter content.