Parengarenga Incorporation is not just focused on producing quality sheep and beef.
General manager Jon Brough, assisted by farm manager Kathryne Easton and others,
has wide-reaching visions of what the future holds to make the best use of the land.
One initiative they are investigating is the use of a carboniser machine to turn
forestry waste into charcoal, BioChar.
They have researched what is happening in Australia with the technology where the
product produced can be used to offset carbon emissions.
All going well, Parengarenga would like to see the same results on this side of the
The machine is fed with slash and waste from a forestry skid site, which is then
turned into something far more useful.
it’s a cooking process where we load it to a certain temperature and
then hold it at that temperature till it pyrolyses and produces a
carbon product. From there we’re going to look at options around
utilising the carbon either by applying it to the pasture or using it as
an animal feed in terms of an animal lick,” Easton said.
She suggests they will look at adding molasses or something similar to encourage
stock to eat it and by offering the stock access to the mix they could reduce the need for drenching.
The carboniser they are trying is a small machine but if successful they will look
at bigger machines that could also provide usable energy to power houses.
For environmentally focused Easton the project fits well within her mantra and the
incorporation’s values of doing the right thing by the soil.
grown a tree, you’ve got a waste product. We turn that waste product
a valuable product, add it back to our pasture and the cycle continues.
The land becomes more effective on the next forestry rotation as well
so you live with a minimal amount of trash.
“So, it’s a really nice cyclic evaluation of a product that would otherwise just
see this project as an exploration into our future as we analyse our
to head towards a carbon-neutral, methane-reduced future. This is a
unique part of the country with a Maori incorporation on a journey with
their whenua with aspirations to make a difference in the national and
international agricultural market arena.”
Don Coyne from ANZBI was in NZ for 10 days in June leading up to the workshops hosted by Dung Beetle Innovations in Whenuapai on 19-20 June. Below is a link to Don’s report on his biochar experiences in NZ.
Linked here is the first of two articles in this month’s edition of NZ Lifestyle Block magazine, featuring the work of BNNZ committee members. I suggest supporting the magazine by buying yourself a hard copy.
We have a small woodlot of eucalyptus, black walnut and Australian
Blackwood. The trees have not been pruned or thinned recently and there
were five large (20m) pine trees overshadowing some areas. Storms and
natural die off as well as the lack of thinning meant that there has and
is plenty of timber to take out and find a use for.
cutting it all up for fire wood, we bought a small portable sawmill in
late 2018. One unanticipated outcome of this was the large volume of
‘waste’ wood that milling creates. Some trees have such poor form that
yield is only 20% of the log in milled timber. The rest is long thin
strips, often too thin to bother cutting for firewood and too much work
to run through a chipper for mulch.
So what to do with this timber? How about biochar?
A flame cap pit burn has been the method of choice because it allows
long lengths to be used and holes are cheap. We can also dig a shallow
pit relatively easily with the blade on the tractor making it the length
of the scrap timber so I don’t have to cut anything to length.
We find a spot close, but not too close, to the scrap timber pile.
Ideally the timber has dried for a few months but only the early part of
the burn needs to be really dry. You need to be away from hedges and
other potential fire risks.
We do all of our burns in winter,
which makes for much more pleasant working conditions and reduces the
fire risk. The ideal day would have little or no wind and of there was
wind it would be away from close neighbours and the road. Local roads
have been closed several times in the last few years by smoke from
bonfires close to the road (not by me, though!) Make sure you have a
large volume of fire fighting water. We have a 40mm hose nearby that
can put out just about anything. We have also used IBC containers of
water to quench in the past if we are out of hose reach. It is too late
to organise this at the end or if there are problems. Do it in the
A small fire lit in the bottom of the pit with dry
timber gets thing going. Then slowly add larger dry pieces. Once it is
well alight you can add larger and wetter timber, but freshly cut
timber, being soaking wet, will make for a smoky, difficult burn so is
not suitable in any volume. Very large pieces will not always fully burn
down to embers so may need to be taken out at the end and added to the
next burn. Do not use timber with nails, paint or chemically treated.
You will likely end up with contaminated biochar.
Each time you
see ash forming on the embers, add more parallel pieces of timber. The
pit will soon be full of embers. When you run out of timber, time or
enthusiasm, completely fill the pit with water. Any reasonable pile of
embers not completely doused can have enough energy to dry the pile and
restart the fire, so do a good job of this. The next day you can
shovel out the charcoal from the pit, unless you didn’t put it out
properly in which case you will just have ash! It may still be quite
warm so another go with the hose won’t hurt. Depending on the size of the pit, you may have a cubic meter of charcoal at this point.
A new report Co/ our friends at ANZBI which includes some NZ content. Click on the cover image below to download from ANZBI website…
Summary Biochar and wood vinegar are emerging technologies with numerous applications in agriculture and environmental remediation. Advocates and early adopters of these products are well versed in their positive attributes. Biochar, for example, has been shown generally to increase crop yields in tropical latitudes, remediate soil, reduce soil greenhouse gas emissions and sequester carbon amongst many other observed benefits. Yet it is arguably the case that not enough focus has been given in financial feasibility studies to the benefits observed by users of biochar beyond its use as a soil amendment. Existing studies in high income countries tend to focus on soil amendments in low value cereal crops, and with the exception of Joseph, et al., they overlook biochar’s use as an animal feed, for soil remediation and for water use efficiency. This report begins to address this knowledge gap by providing an account of how biochar and wood vinegar users are accruing benefits or disbenefits in their farming operations. In March and April of 2019, the Australian New Zealand Biochar Initiative (ANZBI) surveyed sixteen current users of biochar and six users of Wood Vinegar. The survey found that: • The use of biochar as animal feed is an important emerging market in Australia. Those who feed biochar to cattle do so on a daily basis for the purpose of improved cattle health, improved cattle weight gain, methane emissions reduction and reduced feed cost. • Biochar is being used as a soil amendment to improve the crop yields and the produce quality of higher value crops (fruits, vegetables, nuts, horticulture), but the business case remains challenging for broadacre cereal crops. These users were found frequently to produce their own biochar and to apply it on a monthly or annual basis. • Adding small amounts of biochar and minerals to chemical fertilisers (as has now been commercialised in China) has the potential to increase yield, profitability and quality of vegetables and grains. • Wood vinegar is being used to increase rates of seed germination, reduce fungal diseases and to improve both plant health and crop quality. Users of this product were frequently fruit and nut farmers. Furthermore, the report includes in-depth case studies including biochar’s use in a golf course, for use in an avocado orchard, for use as an animal feed and for use in a potato farming operation. These in-depth case studies exhibit circumstances under which biochar not only breaks even for the user, but is lucrative. A review of the biochar literature examines emerging products and innovations. It highlights the importance of practices such as banded application for improved user value and the high performance of biochar fertilisers. It further remarks on the discrepancy between the literature and the commercial reality.
“A plot of mature miscanthus growing at the FAR research centre at Tamahere was offered to BNNZ members to use for a biochar production demonstration and biochar yield assessment. Miles Pope, Simon Day and Dennis Enright for BNNZ and Peter Brown of MiscanthusNZ met on site on May 21st . We intended harvesting some miscanthus and taking it back to Miles’ yard at Pukekohe to pyrolyse in an open trench as we see this could be an approach that farmers might use. However we found that the miscanthus still had a high moisture content with tops that were still green, which made it unsuitable for trench flame-cap pyrolysis. It is likely to be August before it is sufficiently dry to pyrolyse, so we will not be using it for demonstration purposes. Peter had already offered us some bales of dry miscanthus (harvested more than a year ago) so we collected two big circular bales weighing 220 kg and 240 kg with a total estimated volume of 3 cubic metres. Miles dug a trench with his digger, having dimensions about 0.9 m wide, 0.6 m deep and 4 m long. We then began a fire in the bottom of the trench, and over about 1.5 hours we fed all the miscanthus into the trench. The miscanthus readily pyrolysed and was quenched with water at the conclusion. We produced approximately 1.5 m3 of biochar.”
BNNZ are now hoping that the deferred production of biochar from the FAR block will be progressed after August and that this may lead to crop field trials.
Biochar Network New Zealand (BNNZ) is delighted to hear the government announce in their budget further funding to assist farmers to respond to the impacts of global warming. Continuing with their commitment to moving towards a low carbon economy, providing additional funding to more sustainable land management will be of great benefit to farmers while also enhancing our international trading relationships and local environment.
BNNZ see biochar as one of the tools that can contribute to more sustainable land management. It provides multiple benefits to soil, while increasing fertiliser efficiency and nutrient retention, so reducing the quantity of fertiliser needed as well as reducing losses into waterways and other sensitive ecosystems.
The October 2018 IPCC special report highlighted Biochar (pyrolysis carbon capture and sequestration) as a key negative emissions technology to remove carbon dioxide from the atmosphere. The IPCC notes that even massive reductions in carbon emissions will be inadequate to achieve carbon neutrality by 2050. It notes that there is additional need for large-scale atmospheric carbon dioxide removal to prevent overshooting the 1.5°C temperature threshold. While increased forestry plantings will help, forestry carbon sequestration has land availability limits. Biochar technology is New Zealand’s biggest single technological opportunity to sequester carbon in soils for the long term while also achieving other productivity and environmental benefits.
Now is the time for NZ government policy to include biochar in Zero Carbon legislation, as well as to provide support for programs that assist large scale production and use of biochar in mainstream farming practice.