Biochar - miracle cure?

2015-05-17 10:05

When I do charcoal-making demonstrations at various shows and open days I am often approached by biochar enthusiasts.

Spurred by interest in the Amazonian “wonder-soil”, terra preta, there has been growing interest in biochar as a soil amendment and a potential carbon sink.

Originally aimed mostly at use as an agricultural soil amendment, the definition of biochar has been refined by the British Biochar Foundation to be: charcoal made using modern technology, from sustainable resources, used for any purpose that will not result in its rapid break down back into CO2 i.e. not burnt!

As such, there are 55 uses of biochar and counting…, but the main excitement remains around it’s use as a soil amendment.

Microscopic view of charcoal

Charcoal has a massive surface area due to the structure of the material it is made from; pores and micropores down to the scale of cells are preserved in a relatively stable form, providing pockets for the adsorption of nutrients, minerals and water, and living spaces for soil microbiota. Essentially a sponge.

Biochar is not a fertiliser (on it’s own it is little else than carbon), but “charged” with nutrients and moisture it may share many of the benefits of compost: improved soil fertility, structure, moisture retention and/or drainage, increased cation exchange capacity and increased microbial activity.

While some studies have shown incredible 800% improvements in crop yield, this is based on pretty poor starting soil. In better soils you are likely to get less of an improvement. One study in the UK showed a 30% improvement in barley yield when high levels of biochar and fertilizer were used together.

While ordinary organic matter added to the soil will be broken down within years (returning it’s carbon to atmosphere as CO~2~ and methane), biochar may remain in the soil for decades, or possibly even millennia!

The combination of these factors has led for some to call for the application of biochar to soil on a massive scale. While some believe that it can be a major tool in combating climate change, there are some considerable concerns being raised about some of these schemes and their implications. It’s these kind of concerns that have led to the BBF definition’s specification of “modern technology” and “sustainable resources”.

As ever, there is sense and non-sense at both extremes and the truth, most likely, lies somewhere in the middle. On a small scale, using charcoal from coppiced woodlands, I’m fairly confident that I’m doing a bit to combat climate change, increase biodiversity and grow more tomatoes.

If you’d like to join in, biochar is available here in small bags or large!

Iain Loasby

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Lots of hedges getting laid this year

2015-02-04 05:39

Lots of straight hazel growing from a stool

The opportunity to work in Furzefield Woods LNR, Potters Bar has been a bit of a blessing.

Most hazel coppice in this part of the world is overstood by 60-70 years and derelict to the point of producing little more than firewood and charcoal. It can take 2 or 3 cuts or more – perhaps over as much as 20 years – to restore derelict coppice back to something productive and workable.

Thanks to the wildlife benefits of coppicing, Furzefield has previously been “cut to waste” – the timber was mainly chipped onto the paths to try and control the mud. This gives me a bit of a head start and means there’s quite a few more usable rods coming out each year, but there’s a long way to go to get to the kind of quality and volumes you’d see in an “in-cycle” wood in Hampshire, say.

There’s been a bit of a rush on stakes and binders this year. It’s good to know that there’s lots of people wanting to get hedge laying (see you there?), but unfortunately I could have sold all the stakes and binders I got out of Furzefield 2 or 3 times over almost by the time I started cutting!

A trip down South was in order to get some better rods for hurdles and I’ve managed to add some stakes and binders in on top.

If I’ve had to let you down on stakes and binders already I will be in touch shortly, if you’ve yet to ask, now’s the time!

Iain Loasby

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Highgate Wood Heritage Day

2014-08-27 15:18

Twig pencils

Twig pencils at the ready for Highgate Wood Heritage Day

With a bit of luck I’ll actually be making some charcoal there, too.

Iain Loasby

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North London Charcoal once again

2014-07-12 14:11

… eventually.

It was hoped that the 1st-4th August would have seen Queen’s Wood in Haringey becoming a site of charcoal production again for perhaps the first time in living memory.

Unfortunately, I’ve not been able to find an additional qualified First Aider able to spend the night with me and the retort in the wood in time, so it’ll be a bit longer before charcoal returns to Queen’s Wood.

I will be there for the Family Fun Day on Saturday with the retort on display, but no charring action this time.

Iain Loasby

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National Coppice Federation

2013-04-30 07:34

This last weekend I took a trip to Malvern in Worcestershire for the inaugural AGM of the fledgling National Coppice Federation.

There were guest speakers, demonstrations of crafts and useful ideas, some nice visits to other peoples’ woods to see how they work, and, of course, some cider and some venison sausages sat around a fire pit. The main business of the occasion was to agree the articles and elect the directors of NCFed.

This is not the first attempt to form a national body to represent coppice workers, with previous efforts in the 90s appearing to peter out for one reason or another, though a number of regional groups emerged to fill some of the needs.

It seems as though there could be some major benefits to having a national association, not least a single entity to represent coppice workers generally – who spoke for coppice on the Independent Panel on Forestry

There are, however, some obstacles to overcome.

“Coppicing” as a term covers a pretty broad range of operations: from near-industrial chestnut coppice making paling by the mile; individual craftsmen; firewood production; charcoal production; old boys who’ve been at it all their lives working the same woods their parents did before them; “upstarts” (like myself) trying to return the remnants of their local coppice to a viable productive state; “conservation coppice” trying to maintain the legacy of wildlife benefits that millennia of coppicing has left us and pretty much every shade of variation in-between. Bringing all this together into a coherent organisation seems like a pretty major challenge in itself.

Then there are the coppice workers themselves and the scars and the baggage and the politics that remain from previous attempts. There seems to be a widespread perception that a national association will be just a talking shop run by paper pushers with little practical use for “the doers” out there working in the woods. If those “doers” don’t make an effort to get involved and influence the way the organisation progresses then that will be a self-fulfilling prophecy.

I’ve had the pleasure of meeting several of the people who now form the “directors” of the National Coppice Federation and I’ll trust them to make a decent fist of pulling something useful together.

I don’t think coppice workers – of whatever variety – should leave them to do it on their own.

Iain Loasby

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