Barley field near Wallington, Hertfordshire. Copyright: Paul Dixon. Licensed for reuse under a Creative Commons Licence.
Biochar increases crop productivity in many tropical soils. The reasons probably include improved water retention, reduced leaching, and better availability of nutrients to plant roots. In temperate conditions, studies have been fewer in number and haven’t produced results that are as clear. A new study[1] adds usefully to our knowledge.
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Alfred Gathorne-Hardy and colleagues at Imperial College, London applied varying amounts of biochar and of nitrogen fertiliser to barley. Their research showed that biochar improved yields substantially but only in those trials when large amounts of artificial fertiliser were also applied. Adding 20 tonnes a hectare (2 kg a square metre) of biochar to a soil fertilised with 100 kg of nitrogen a hectare increased the crop yield by over 30%. Loosely put, biochar improves the effectiveness of the nitrogen. But for soils with no added fertiliser, increasingly heavy applications of biochar tended slightly to reduce the crop yield.
This is an extremely interesting result for two reasons. Firstly, it shows that it may be financially rational for UK and other temperate zone farmers to add biochar to the soil. Secondly, the improved crop yields may be arising from greater retention of nitrogen in the soil. This is important because it would probably imply reduced run-off of nitrogen into water courses. Run-off may be the most important source of nitrous oxide from agriculture. (Nitrous oxide is a potent global warming gas, three hundred times worse than CO2.)
Let’s examine these two hypotheses in turn. First, the financial incentive to add biochar. Many barley farmers have an unsaleable surplus of straw. Charring the straw will cost money but biochar will usually remain in the soil for many years. In the tropics, many biochars seem to have half-lives of several centuries. So if the result identified in the paper is replicated in the field biochar will add to crop yields for many years. Typical barley yields are about 6 tonnes per hectare and recent prices for good quality grain have averaged about £80 per tonne. A 30% increase in yields is therefore worth about £150 a hectare a year. Over ten years the undiscounted value is perhaps £1,500, a number vastly greater than the cost of charring 20 tonnes of straw. I guess that the cost of the biochar might eventually be as low as £10 per tonne.
So it may make financial sense to apply biochar to UK soils, even before considering the impact on emissions. We should therefore move on to the impact on GHGs. At today’s prices in the European Emissions Trading system, the value of 20 tonnes of pure carbon newly sequestered in the soil is more than £700. (Carbon dioxide, currently trading at more than £10 a tonne has 3.67 the weight of carbon.) Also important is the impact on nitrous oxide emissions. If biochar reduces nitrous oxide emissions by holding nitrogen better in the soil, the value will add to the impact of CO2 reduction. IPCC studies suggest that 1% of the nitrogen in fertiliser ends up as nitrous oxide gas, usually through interaction with water in fields and in drainage ditches at field edges. More recent studies suggest that the actual number may be much higher, particularly in wet climates like the UK. But even the IPCC figure suggests that 1 kg of nitrous oxide emissions per year – equivalent to about 300 kg of CO2 – will be avoided, perhaps for many years, by the use of biochar. But let’s assume the nitrous oxide reduction only persists for ten years. The value of this at £10 per tonne of CO2 equivalent is about £30.
Here’s a highly simplified summary of the benefits of biochar, at today’s crop and carbon permit prices (all numbers are per hectare):
| Cost of charring 20 tonnes | £200 |
| less | |
| Benefit of improved yields for 10 years | £1,500 |
| Shadow value of 20 tonnes of sequestered biochar as pure carbon | £700 |
| Shadow value of avoided nitrous oxide emissions | £30 |
| Net benefit | £2,030 |
|---|
The key conclusions are that yield improvement values dwarf the monetary value of carbon emission improvements but also that it should be worthwhile sequestering biochar even if yield gains are negligible or non-existent.
Appendix: some data on straw
Barley straw weighs approximately the same as the grain from a field. So each hectare produces about 6 tonnes of straw per year. A tonne of straw might produce char of about a third of the weight. So each hectare should produce char of about 2 tonnes per year of crop production. To apply 20 tonnes per hectare thus requires about 10 hectares of straw. But even if biochar lasts as little as 10 years, the straw per hectare will produce enough char to generate the crop productivity improvements. So there is no need for external inputs of biomass to produce the fertility improvements – the biochar can be generated on the farm itself.
Footnote
[1] Alfred Gathorne-Hardy and others, ‘Biochar as a soil amendment positively interacts with nitrogen fertiliser to improve barley yields in the UK’, IOP Conference Series: Earth and Environmental Sciences, 6 (2009), 372052 http://bit.ly/Gathorne-Hardy2009 (doi:10.1088/1755-1307/6/7/372052).
Tags: agriculture, Alfred Gathorne-Hardy, biochar, emissions trading
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I guess the question then becomes how many years can you theoretically continue to add the biochar before the benefits start to wane ?
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Depends on how deep you can cultivate it in. The Australians have talked about 180 T / Ha to a 1 meter depth using sub-soiler type chisel plows.
The pot studies I’ve seen show a decline in plant benefits at > 30% char by volume.
? What is the ” Shadow Value” of more recalcitrant organic carbon, ( living biomass & Glomalins)?
and the increased root growth when associated with higher MYC fungi infection rates?Biochar Soil Technology…..Husbandry of whole new orders of life
Biotic Carbon, the carbon transformed by life, should never be combusted, oxidized and destroyed. It deserves more respect, reverence even, and understanding to use it back to the soil where 2/3 of excess atmospheric carbon originally came from.
We all know we are carbon-centered life, we seldom think about the complex web of recycled bio-carbon which is the true center of life. A cradle to cradle, mutually co-evolved biosphere reaching into every crack and crevice on Earth.
It’s hard for most to revere microbes and fungus, but from our toes to our gums (onward), their balanced ecology is our health. The greater earth and soils are just as dependent, at much longer time scales. Our farming for over 10,000 years has been responsible for 2/3rds of our excess greenhouse gases. This soil carbon, converted to carbon dioxide, Methane & Nitrous oxide began a slow stable warming that now accelerates with burning of fossil fuel.
Wise Land management; Organic farming and afforestation can build back our soil carbon,
Biochar allows the soil food web to build much more recalcitrant organic carbon, ( living biomass & Glomalins) in addition to the carbon in the biochar.
Biochar, the modern version of an ancient Amazonian agricultural practice called Terra Preta (black earth, TP), is gaining widespread credibility as a way to address world hunger, climate change, rural poverty, deforestation, and energy shortages… SIMULTANEOUSLY!
Modern Pyrolysis of biomass is a process for Carbon Negative Bio fuels, massive Carbon sequestration,10X Lower Methane & N2O soil emissions, and 3X Fertility Too.
Every 1 ton of Biomass yields 1/3 ton Charcoal for soil Sequestration, Bio-Gas & Bio-oil fuels, so is a totally virtuous, carbon negative energy cycle.Biochar viewed as soil Infrastructure; The old saw;
“Feed the Soil Not the Plants” becomes;
“Feed, Cloth and House the Soil, utilities included !”.
Free Carbon Condominiums with carboxyl group fats in the pantry and hydroxyl alcohol in the mini bar.
Build it and the Wee-Beasties will come.
As one microbiologist said on the Biochar list; “Microbes like to sit down when they eat”.
By setting this table we expand husbandry to whole new orders of life.This is what I try to get across to Farmers, as to how I feel about the act of returning carbon to the soil. An act of pertinence and thankfulness for the civilization we have created. Farmers are the Soil Sink Bankers, once carbon has a price, they will be laughing all the way to it.
One aspect of Biochar systems are Cheap, clean biomass stoves that produce biochar and no respiratory disease. At scale, the health benefits are greater than ending Malaria.
A great example;
http://www.unccd.int/publicinfo/poznanclimatetalks/docs/Natural%20Draft%20Stove.pdfThe biochar Fund is also doing amazing work in the developing world;
http://terrapretapot.org/Also , I would like Rebut the BioFuelWatch folk’s recent criticisms with the petition of 1500 Cameroon Farmers;
The Biochar Fund
http://biocharfund.org/
and to explain their program;
http://biocharfund.org/index.php?option=com_content&task=view&id=26&Itemid=46The USDA-ARS have dozens of studies happening now to ferret out the reasons for char affinity with MYC fungi and microbes, but this synergy is solidly shown by the Japanese work, literally showing 1+1=3
Senator / Secretary of Interior Ken Salazar has done the most to nurse this biofuels system in his Biochar provisions in the 07 & 08 farm bill,
http://www.biochar-international.org/newinformationevents/newlegislation.htmlCharles Mann (“1491″) in the Sept. National Geographic has a wonderful soils article which places Terra Preta / Biochar soils center stage.
http://ngm.nationalgeographic.com/2008/09/soil/mann-textBiochar data base; TP-REPP
http://terrapreta.bioenergylists.org/?q=nodeNASA’s Dr. James Hansen Global warming solutions paper and letter to the G-8 conference, placing Biochar / Land management the central technology for carbon negative energy systems.
http://arxiv.org/ftp/arxiv/papers/0804/0804.1126.pdfThe many new university programs & field studies, in temperate soils; Cornell, ISU, U of H, U of GA, Virginia Tech, JMU, New Zealand and Australia.
Glomalin’s role in soil tilth, fertility & basis for the soil food web in Terra Preta soils.
UNCCD Submission to Climate Change/UNFCCC AWG-LCA 5
“Account carbon contained in soils and the importance of biochar (charcoal) in replenishing soil carbon pools, restoring soil fertility and enhancing the sequestration of CO2.”
http://www.unccd.int/publicinfo/AWGLCA5/menu.phpThis new Congressional Research Service report (by analyst Kelsi Bracmort) is the best short summary I have seen so far – both technical and policy oriented.
http://assets.opencrs.com/rpts/R40186_20090203.pdf .Given the current “Crisis” atmosphere concerning energy, soil sustainability, food vs. Biofuels, and Climate Change what other subject addresses them all?
This is a Nano technology for the soil that represents the most comprehensive, low cost, and productive approach to long term stewardship and sustainability.
Carbon to the Soil, the only ubiquitous and economic place to put it.
Cheers,
Erich J. Knight
Shenandoah Gardens
540 289 9750Biochar Studies at ACS Huston meeting;
Most all this work corroborates char soil dynamics we have seen so far . The soil GHG emissions work showing increased CO2 , also speculates that this CO2 has to get through the hungry plants above before becoming a GHG.
The SOM, MYC& Microbes, N2O (soil structure), CH4 , nutrient holding , Nitrogen shock, humic compound conditioning, absorbing of herbicides all pretty much what we expected to hear.578-I: http://a-c-s.confex.com/crops/2008am/webprogram/Session4231.html
579-II http://a-c-s.confex.com/crops/2008am/webprogram/Session4496.html
665 – III. http://a-c-s.confex.com/crops/2008am/webprogram/Session4497.html
666-IV http://a-c-s.confex.com/crops/2008am/webprogram/Session4498.html
Company News & EU Certification
Below is an important hurtle that 3R AGROCARBON has overcome in certification in the EU. Given that their standards are set much higher than even organic certification in the US, this work should smooth any bureaucratic hurtles we may face.
EU Permit Authority – 4 years tests
Subject: Fwd: [biochar] Re: GOOD NEWS: EU Permit Authority – 4 years tests successfully completedDoses: 400 kg / ha – 1000 kg / ha at different horticultural cultivars
Plant height Increase 141 % versus control
Picking yield Increase 630 % versus control
Picking fruit Increase 650 % versus control
Total yield Increase 202 % versus control
Total piece of fruit Increase 171 % versus control
Fruit weight Increase 118 % versus controlHOMEPAGE 3R AGROCARBON: http://www.3ragrocarbon.com
Also:
EcoTechnologies is planning for many collaborations ; NC State, U. of Leeds, Cardiff U. Rice U. ,JMU, U.of H. and at USDA with Dr.Jeffrey Novak who is coordinating ARS Biochar research. This Coordinated effort will speed implementation by avoiding unneeded repetition and building established work in a wide variety of soils and climates.
http://www.EcoTechnologies.comHopefully all the Biochar companies will coordinate with Dr. Jeff Novak’s soils work at ARS; http://www.ars.usda.gov/pandp/people/people.htm?personid=24434
I spoke with Jon Nilsson of the CarbonChar Group, in their third year of field trials ;
An idea whose time has come | Carbon Char Group
He said the 2008 trials at Virginia Tech showed a 46% increase in yield of tomato transplants grown with just 2 – 5 cups (2 – 5%) “Biochar+” per cubic foot of growing medium. http://www.carbonchar.com/plant-performanceLow Tech Clean Biochar;
http://holon.se/folke/carbon/simplechar/simplechar.shtml -
Trackback from temperate on Thursday 7 May 2009 at 7.18pm
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“The Biochar Revolution” with “The Biochar Solution”
http://biochar-books.com/
The Biochar Revolution collects the results and best practical advice that these entrepreneurs have to offer to the biochar community. When practice and theory advance to the point where they meet in the middle, then we will truly see a biochar revolution. -
RE …..” the cost of the biochar might eventually be as low as £10 per tonne.”
Could you please specify how the production cost of the biochar has been engineering designed? as setting up and operate an modern biochar production plant in the temperate climatic zone countries – which meets the environmental and industrial norms and standards – would possibly result far higher biochar production costs than the indicated targeted £10 per tonne.
TKS
Edward Someus, —- http://www.3ragrocarbon.com
(Coordinator and key technology designer for the official European Union accredited biochar standardization programme REFERTIL).
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