Monday, September 17, 2007

Terra Preta soils - can the NT reach this level of improved soil carbon

Terra Preta: Black is the New Green

Carbon sequestration faces some major hurdles. Technical geosequestration methods could pump large amounts of CO2 deep underground but are still under development. On the other hand, natural methods that store carbon in living ecosystems, such as trees, may be possible in the short term but require huge swathes of land and are only as stable the ecosystems themselves. An ideal solution, however, would combine the quick fix of biological methods with the absolute potential of technical ones. Terra preta [sometimes seen as terra petra] may do just that, as a recent article in the journal Nature reveals. Soil sequestration of carbon has many proponents, incluidng a number of very experienced and knowledgeable scientists, in numerous countries. Australia has been slow to solidly examine this option, yet our soils - some of the oldest and most depleted on planet earth, could really get a kick start with higher soil carbon levels.

Amazonian Dark Earth, or "terra preta do indio", has mystified science for the last hundred years. Three times richer in nitrogen and phosphorous, and twenty times the carbon of normal soils, terra preta is the legacy of ancient Amazonians who predate Western civilization. Scientists who long debated the capacity of 'savages' to transform the virgin rainforest now generally agree that indigenous people transformed large regions of the Amazon into amazingly fertile black earth. The Amazonians' techniques remain an enigma but are believed to have used slash-and-smoulder to lock half of the carbon in burnt vegetation into a stable form of biochar instead of releasing the bulk of it into the atmosphere like typical slash-and-burn practices.

The difference between terra preta and ordinary soils is immense. A hectare of metre deep terra preta can contain 250 tonnes of carbon, as opposed to 100 tonnes in unimproved soils from similar parent material, according to Bruno Glaser, of the University of Bayreuth, Germany. To understand what this means, the difference in the carbon between these soils matches all of the vegetation on top of them. Furthermore, there is no clear limit to just how much biochar can be added to the soil.

Claims for biochar's capacity to capture carbon sound almost audacious. Johannes Lehmann, soil scientist and author of Amazonian Dark Earths: Origin, Properties, Management, believes that a strategy combining biochar with biofuels could ultimately offset 9.5 billion tons of carbon per year-an amount equal to the total current fossil fuel emissions!

Indeed, there is profit to be made in this black earth, for if green is the new black, then black could be the new green. Biofuels are touted as 'carbon neutral', but biofuels combined with biochar [ now generally referred to as agrichar] together promise to be 'carbon negative'. There are a number of competing technologies and some have fuel oil as a potential product, with agrichar the byproduct.

One technology - the Eprida technology uses agricultural waste biomass to produce hydrogen-rich bio-fuels and a new restorative high-carbon fertilizer (ECOSS) . Trials in tropical or depleted soils with ECOSS fertilizer sustainably improves soil fertility, water holding and plant yield far beyond what is possible with nitrogen fertilizers alone. The hydrogen produced from biomass can be used to make ethanol, or a Fischer-Troupsch gas-to-liquids diesel (BTL diesel), as well as the ammonia used to enrich the carbon to make ECOSS fertilizer. Ecocarbons from Australia have another system, with Dynamotive Energy Systems of Canada also in the mix.

Terra preta's full beauty appears in this closed loop. Unlike traditional sequestration rates that follow diminishing marginal returns-aquifers fill up, forests mature-practices based on terra preta see increasing returns. Terra preta doubles or even triples crop yields. More growth means more terra preta, begetting a virtuous cycle. While a global rollout of terra preta is still a long way off, it heralds yet another transformation of waste into resources.

Agricultural Carbon Wastes to Useful Industrial Carbon

New renewable industry may turn farm waste to commercially viable carbon

A pilot factory based in Gunnedah, NSW, and perhaps with a second unit in Toowoomba, Queensland, could spearhead the emergence of an industrial process able to turn farm wastes into charcoal beads, thereby providing a new source of renewable energy.

Eco-Carbons Pty Ltd's spokesman, Michael Neil, says the thrust of the process is to convert organic waste materials such as cereal grain 'seconds', husks, fruit stones, nut shells, and even straw, into carbon products suitable for industrial and domestic applications. "Our research and development programme has given us the confidence to trial carbonisation plants to produce, under controlled conditions, charcoal fuel beads for a range of applications in Australia," Mr Neil said. "The energy given off sustains the kiln itself, plus delivers surplus energy that can even be channelled into an electricity grid." Could this be a suitable application for the mountains of wasted, discarded "shells" of many agricultural products? Many have tried before, here in Australia and overseas, with the utilisation of rice husks a key issue in Asia, for example. Almost all have failed!

The plant's three-stage process involves milling, the formation of beads using natural binders, prior to churning out lightweight and highly porous carbon fuel beads. As a bonus the construction industry stands to benefit from a spin-off product, namely lightweight concrete, using these beads as an aggregrate substitute which should help reduce building costs.

Then there's the interesting possibility of providing horticultural industries with a product able to retain water and stimulate plant growth without suffering from high evaporation rates. Mr Neil says the associated benefits from the process also could see the provision of material with good insulation properties, plus improved soil properties since the end product is non-toxic. Australian soils are deficient in soil carbon, commonly in the form of organic matter, but there are soils elsewhere in the wolrd, notably the terra petra" soils of a few areas of the Amazon that do have a broadly similar carbon material in them.[ see other post]

Originally a Canadian initiative, the task now is to acquire venture capital to set up a fully operational site, with Gunnedah currently looking to be the most likely location.

* More information is available on:

Friday, September 14, 2007

Great Turf - Great Frontage .........Great Business!

Appearances do count but water is precious……… YOUR bit for the environment!

Peter Harrison –

Many businesses want their premises to look smart, neat and tidy, both inside and out. The old adage of “initial impressions count” might have been said with business in mind.

Effort and money goes into a neat, turfed street frontage at a business. In the NT, watering of the area is vital to maintain appearances, with most having some form of pop-up sprinklers. But they are often a cause of frustration.

In numerous areas, vandals or other incidents damage the sprinkler, they commonly over spray on to hard surfaces and with our intermittent power supply , suddenly the timer operates in the middle of the day, spraying customers. As well, many, if not all over irrigate or supply water in a fashion that does not provide a suitable soil moisture regime, which should be deeper watering, less frequently.

The modern solution is the Kapillary Irrigation Sub Surface System, or KISSS. Already widely used in eastern states to improve water efficiency it can be a great option here too. More information at This system is usually cost comparable with sprinklers, but with superior operational benefits.

· “Anytime” watering when plants need it most without interfering with business operations
· Wide area underground watering
· Extremely high water use efficiency – commonly save 50% over sprinkler use
· NO over spray on hard surfaces or roadways
· Reduced cost of irrigation, due to reduced water use and low pressure systems
· Lowered maintenance

Even without improved water use efficiencies, addressing issues of suitable species choice, adequate plant nutrition, weed management, thatch and mowing height and frequency can save you many dollars. Consider revisiting what you do in these areas; seek professional advice, do not rely on your mowing contractor – they make money by cutting more grass and selling more services. You want to reduce their costs, while maintaining or improving aesthetics.

As well as improved water use efficiency, many premises may wish to consider rainwater capture off the roof. This is a very practical option for business, as large roof areas of shed facilities used in conjunction with, for example 30 - 60KL of tank storage [above or below ground in many different forms] can provide adequate water for many on site uses, for around $5 - 7000. This water use includes toilet flushing, vehicle washdown and some irrigation. It reduces polluted stormwater flows, and improves the harbour water quality by reducing these inflows, for most stormwater ends up there. Yes…….there is a cost, but green businesses are often perceived as “good” businesses by customers.

With all of us needing to do more environmentally, these options are technically and financially feasible for the NT.

Tuesday, September 11, 2007

Sequestering Carbon in YOUR Soil - Are There $$ In It For Me?

Sequestering carbon in soil is not a new concept. It happens naturally, but can it be enhanced on farm and can it actually make some dollars for me, on my farm?

The NSW experience is worth examining in some detail, as a similar system could be useful in the tropics as well. There are a number of links with details on the scheme provides access, as well as several additional links, with more information.

Tropical regions also lose carbon, with fire the major problem. That may not be a significant issue on many horticulture, pasture and cropping areas, but it can be in native pasture areas where irregular burning occurs.

Annual horticulture will normally benefit from the additional carbon stored in soil, with superior moisture storage in the soil, plus improved nutrient retention, better soil tilth and a higher soil microbiological regime. And those characters may even add to yield and direct economic returns. The carbon can come from compost, mulch, green manure crops, plant residuals such as leaf drop and plant roots, but management must be directed to gain benefit from the carbon.

Benefits need to measured and a value attributed, but it does appear to show some promise. A note of caution though as one of the carbon trading schemes in NSW has appeared shaky.......and may cease.

We are interested in developing this system further and would welcome interaction with rural users in the tropics.