Cadmium soil contamination in NZ

I think the following should be of interest in NZ based on the levels of Cd contamination in some of our soils. There are other similar research finding coming from China. I posted a link to a NZ PhD thesis on the contamination issue in April at the ABE FB page that fails to mention biochar as a potential solution.

The effect of several activated biochars on Cd immobilization and microbial community composition during in-situ remediation of heavy metal contaminated sediment


Chemical activation and microwave assisted activation were adopted to modify biochar. Activated biochars were characterized by SEM, BET, FTIR, XRD and XPS. Raw biochar, activated biochars and commercial activated carbon were compared as remediation strategies for sediment from the Xiangjiang River containing 14.70 mg/kg Cd. After the treatment by activated biochar, the overlying water and pore water concentration of Cd decreased by 71% and 49%, respectively. And the threat of heavy metal along with bioavailability of Cd was depressed. Moreover, the immobilsation of Cd in sediment was related to BET surface area and the content of oxygen containing functional groups of activated biochars. Furthermore, a PCR-DGGE-based experiment was performed for the detection of microbial community. The indigenous microbial community was affected and new microbial community appeared after treat by activated biochar. Activated biochar can be used as an inexpensive and efficient in situ remediation material of sediment containing metal.

Biochar workshop near Nelson

The biochar workshop tour finished in Gisborne on Friday. The tour was an intense 3 weeks of travel and action leaving behind a long trail of followup actions and emails. And no time for the monthly newsletter. It will take some time to catch up… and now the Feildays starts Wednesday and we hope to be waving a black flag there as well…

This report has been forwarded by the biochar community group based on Motueka, Carbon Action Aotearoa…

Dennis and I are very grateful for their support during our stay for the Nelson workshop and the preceding public forum in Motueka that CAA organised.

More on this and the other workshops soon.

Click on image to link to the cutting or you can search for it here (page 20)


Carbon Action Aotearoa event in Motueka, 28May

A click on the image opposite should lead to a legible version of this article, published in the Nelson leader on 17 May.

We’ve been getting great support from CAA in Motueka for the Nelson workshop on 29 May. Katerina and her team are organising a free public forum on the evening before the workshop.

Details: Free one-hour biochar introductory evening: Monday 28th May 7.30 pm at MOTEC, Parklands School, opposite the library in Pah St. Motueka. (Koha for refreshments and venue hire welcome).

Biochar and kiwifruit industry

Zespri have been kindly supporting our efforts to educate and inform the kiwifruit industry on opportunities related to biochar production and application.

They have published a short article in their latest industry magazine (linked from their banner, above).

Zespri have recently provided some support to research related to biochar through a Waikato University internship but they are not endorsing the use of biochar products.

The nascent biochar industry needs to work with agriculture industries in NZ to validate claims and ensure safe application of new products. Hopefully, the research community will also become more active and interested but this may only come from more funding.

HortNZ… followup article

Biochar: the renaissance of an ancient practice for a sustainable future

HortNZ have kindly supported our workshop marketing activity with the inclusion of a followup story  to the Robin Boom article published in their January edition of their magazine, NZGrower. I covered that in an earlier post:

You can access a copy of the article from the page links below.

click to link to PDF page

NZGrower Vol.73-03, pg30

click to link to PDF page

NZGrower Vol.73-03, pg31

OWNZ publishes biochar article

Reviving an ancient soil technology: Biochar

Organic Winegrowers NZ magazine

Biochar article

Organic Winegrowers NZ have published an article in their latest “organic matters” magazine focused on biochar and supporting the biochar workshop tour coming up next month. All of the workshops are in wine or vine country…

You can access the article pages from the magazine by clicking on the adjacent cover image or the article title, above.

Pukekohe biochar on Earth Day

Source: Pukekohe charcoal fire event to make biochar on Earth Day |

“The Pukekohe Anglican Parish is hosting a charcoal fire event for Earth Day on April 22, as part of the Anglican’s Action Network. The event, held at Pukekohe’s St Paul’s Anglican Church on Buckland Rd, will see a one kilogram block of wood burned for each person in attendance, to make biochar, which will be buried, with fruit trees planted on top. This technique reduces greenhouse emissions by avoiding the release of carbon as the wood decays. To place a block of wood on the fire and to learn more about biochar, the event will take place from 9-11am, followed by a sausage sizzle at 11.30am and the planting of the trees at 12.30pm. A gold coin donation is asked for, to help the parish continue its sustainability work. For more information call John, 2381357.”

BiogroNZ support for biochar workshops

And while I’m on the workshop article theme (last two posts), Biogro have also come out in support with a banner in their latest (March) newsletter. I can’t find a newsletter archive on their website so the best I can do is a C&P from my email newsletter copy:As the text is illegible!:

“Rebuilding and retaining carbon in the soil is fundamental when farming organically. Returning organic matter of various types to the soil is a mandatory and standard process. In line with this is using biochar, which is charcoal produced for application to soil. Workshops are being held across May/June 2018 with a collaboration between AllBlackEarth and NZ Biochar to present information and demonstrations on making and using Biochar. For all inquiries and to make a booking, head to the AllBlackEarth events website.”

Note that the link provided in their newsletter was faulty (corrected, above).

Nelson Grape&Wine biochar article

Nelson Grape & Wine magazine have kindly published an article for ABE, ahead of the upcoming biochar workshop tour, and specifically, the Nelson workshop on 29 May at Kaimira Wines.

As their past magazines are available from their website (but not yet this issue), I’m sure they won’t mind me providing a link to the article on page 8 of their summer 2017/18 issue.

You can click on the left image for a direct link to the article but maybe better viewing from the magazine (link above).

More about the Nelson workshop can be found here:

HortNZ biochar article

I’ve been remiss is publishing posts to ABE this month. A few reasons for this: busy with the biochar workshop tour planning; laziness… its so much easy just to flick a news story to the ubiquity of facebook and the ABE FB page (maybe this will soon change!); and the usual issue of no real NZ content being available to me. But here is a NZ focus article…

Robin Boom’s article was published in a recent edition of the HortNZ magazine: NZGrower Vol 73 No 1. Its a very well written article and kudos on HortNZ for publishing. This is a subscription magazine, available from the HortNZ website. They offer a free sample but unfortunately, the freeby is already at Vol.73 No.2. I think Robin’s article was was January 2018. Here are two links to PDF’s of his article (I’m seeking HortNZ permission, but if I don’t get, I’ll need to take the links down):

We have submitted a new article to HortNZ as part of our workshop marketing efforts. We have tried to address the issues raised by Robin at the end of his article as follows:

Robin Boom ended his excellent article on biochar (NZGrower Vol 73 No 1) by highlighting some hurdles and challenges for a budding NZ biochar industry. We address these issues as follows:

  1. Cost and availability: it is true that the biochar market in NZ is very small. There are a number of pathways to growth, depending on biomass resource, production scale and desired application. Three examples: (1) Frank Strie, a biochar entrepreneur in Tasmania is being contracted to process vine and orchard prunings into biochar onsite using his kontiki kiln designs. This is a very low cost business entry model that can easily be replicated all over NZ. There are a number of NZ producer/entrepreneurs listed on the ABE website who are trying to establish sales and supply reputation; (2) folk are making their own biochar for little more than the ‘cost’ of labour. Farmer cooperation could supply large volumes into most communities using artizan fire management practices or low cost equipment; (3) very low cost biochars are available from some locations in NZ, derived from inefficient biomass boilers. There are many more NZ scenarios that I could describe at length but this needs its own story.
  2. Transport costs: It is true that biochar in a post-production, dry state could be volatile and has low bulk density. Fresh, dry charcoals have been known for self-ignition from a cold start. The chemistry behind this is interesting but not relevant to biochar. Charcoal needs water on its path to becoming a biochar… a vital ingredient to life in the biochar. Transport costs should be addressed by local markets for production and supply of both raw and amended/specialised biochars … poorly utilised biomass is everywhere and should be converted to biochar as a common localised activity (home garden to commercial scales).
  3. Application methods: This is a interesting and exciting area of development around the world. Biochar can be modified to be the carrier of choice for nutrients and beneficial soil life. Biochar is best mixed with compost during production, reaping rewards in the compost process as well as the biochar. Bartlett in USA and UK are air-spading biochar under mature / diseased / urban trees with amazing success. In NZ, water-spading is being investigated. Existing spray systems can apply biochar as an emulsion to the under-story. There are many other biochar application ‘cascades’, providing practical environmental services on the way to the soil.