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Invention helps growers be kind to the planet

By Exeter Express and Echo  |  Posted: May 02, 2013

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TWO men, one a former aviation logistics manager, the other a former coal miner, both lifelong gardeners, are pioneering the eco-friendly production of an eco-friendly compost.

Robin and Geoff from Exeter, discovered that mixing biochar, or treated charcoal, with either composted equine manure or vegetable matter, and stirring it into your soil, is like a magic potion for your plants.

Not only were they the first people to start manufacturing the concoction, but they also invented the first machine of its kind to create the central ingredient, biochar.

And not only is the biochar itself incredibly fertile and good for our soil, but Geoff and Robin's invention of biochar soil improver is also helping to combat global warming.

This is how: Trees release life-giving oxygen while absorbing harmful carbon dioxide, known as a cause of global warming. The trees store the carbon, which is released when it dies or its wood is burnt. But when wood is turned into charcoal, this harmful carbon is fixed in the charcoal itself, which is then buried in the ground as compost – and the soil loves it.

"I was watching a programme about the Mayan Indians on TV living in large urban areas," explains Geoff, 69. "But the ground around them was really poor and they couldn't work out how to grow their own food for themselves. And then they discovered a substance called black earth, or terra preta."

The Indians found this substance, a volcanic ash, charcoal, manure mix, to be extremely fertile.

"The problem with standard manures is that they need replenishing because all the goodness you're putting into the soil eventually dries or runs through sandy soil," Geoff explains. "But biochar is an incredibly good additive because it's like a sponge, once it's in there, it's in there."

So effective is the compost in retaining moisture that Geoff's "very hungry" tomatoes needed half the amount of water. "And it's such a simple process," Robin, 53, continues. "Because charcoal is so porous it has a large internal surface area and what it does when you put it in the soil is absorb the nutrients and water, and provides a cosy home for bacteria and nematodes and fungus that your plants need in order to be able to grow."

Geoff and Robin also make a vegetarian compost using vegetable waste rather than manure, for their vegetarian and vegan customers.

"Interestingly," said Robin, "the reason we're doing it, is because it works, but it is eco-friendly."

Not long after conception in 2010 the duo conducted trials, which worked really well. There were lots of willing experimenters at the allotments," says Geoff. "We gave them the compost and said do what you like with it, and we had nothing but good reports back."

But to create their wonder compost they needed a bounteous supply of wood and manure. Cue donkeys.

"Geoff rang me up one day and said have you thought about the Donkey Sanctuary for manure, which has 1,000s of donkeys and a huge amount of poo, which they process properly," continues Robin.

"As part of their waste treatment, or composting, process they used to use the liquid element to run through their willow beds which are harvested every three years," takes over Geoff. "At the same time we were running out of charcoal fines in Devon and knew we'd have to start producing our own. They asked us what they could do with their willow trees and it occurred to me that if we built our own machine, we could use their willow for our charcoal. Now it's our only source for our charcoal."

Next the duo just had to create their own charcoal maker.

The mobile Exeter Retort was the first of its kind in the world and produces the biochar releasing 75 per cent fewer pollutants into the atmosphere that traditional kilns.

And so eco-friendly is the invention, that the duo won the Low Carbon Innovation Business Award in the Devon Environmental Business Awards 2012.

Next week, as part of International Compost Awareness Week (May 6 to 12), Nicky Scott, co-ordinator of Devon Community Composting Network, will be explaining why it is important to make and use compost.

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  • erichjknight  |  May 05 2013, 5:37AM

    To appreciate the wider applications of Biochar, the use as a feed additive and nutrient management tool, Please review my presentation and slides of this opening talk for the USBI Biochar conference in Sonoma California. This is the third US Biochar conference, after ISU 2010 and Colorado 2009; "Carbon Conservation for Home, Health, Energy & Climate" http://tinyurl.com/cnpcwrs Modern Thermal conversion of biomass burns only the hydrocarbons in that biomass, conserving the carbon for the soil. At the large farm or village scale modern pyrolysis reactors can relieve energy poverty, food insecurity and decreased dependency on chemical fertilizers. Please take a look at this YouTube video by the CEO of CoolPlanet Biofuels, guided by Google's Ethos and funding, along with GE, BP and Conoco, they are now building the reactors that convert 1 ton of biomass to 75 gallons of bio – gasoline and 1/3 ton Biochar for soil carbon sequestration. http://tinyurl.com/cwg5392 If CoolPlanet Biofuels processed the entire projected US biomass harvest in 2030, of 1.6 Billion Tons, the yields would be; 120 Billion Gallons of tank ready fuel ,(The US uses 150 Billion gallons/year), and 0.3 Billion Tons of Biochar The big numbers are jaw dropping, The 0.3 Billion Tons of Biochar, with a surface area of 400 m2/gram means; One Ton has a surface area of 98,000 Acres! Now for conversion fun: 98,000 Acres is equal to 152 square miles!! .... So; 300 Million Tons of Biochar equals 45 Billion Square Miles, or 230 times the entire surface of the earth! Costs; The field to wheel analysis is $1.50/gallon! To review other developments in cleanburning cook stoves, pyrolytic home heating stoves etc. Please review my Sonoma Biochar Conference Report; http://tinyurl.com/c6kgvrf My heroes are the engineers without Borders who have promoted clean cook stoves, Pyrolytic and Gasifing stoves that burn any biomass cleanly and 41% more efficiently. No black-lung no emphysema, no deforestation, all the while building soil carbon for continually sustainable yields. Please look at the work of the Biomass Energy Foundation. At scale, replacement of three rocks in a pot, across Africa would have the health impact equivalent of curing malaria and AIDS combined. Biomass Energy Foundation (BEF) website http://tinyurl.com/6s74af4