Biochar Potential or Pitfall? Carbon Storage vs Soil Quality

[DDDarray]

Biochar could be used instead of lime to buffer acids formed during composting.

[WoodsEndLaboratory]

@DDDarray Waat is the evidence that biochar is a buffer? The high pH from potash might temporarily neutralize organic acids, but they go away on their own anyhow.

[lock2hart]

The Terra preta sites would back up the use of biochar, but there is another naturally accuring way biochar has been 'used' for centuries. Lightning setting forest on fire. The result is lush acres of grassland to support wildlife, because without natures intervention animals could starve. The trees slowly invade to start the process over again and again. I don't have a science background, but I do believe in these simple facts.

[turborabbit1114]

I have been using bio-char in my garden for years now and other than that it absorbs nutrients the first year you use It, I have seen no harmful effects, and its not like someone would use it as a sole fertilizer you still need to add some N-P-K the biochar just holds the N-P-K where the plants can get it, rather than haveing it runoff with the rain.

[doktorandom]

One reason that I can see and am engaged in developing is the quick conversion of animal wastes into more stable materials for ag. Horse manure for example is hard to store, too 'hot' for immediate use in soil amendments and leaches into groundwater in wet climates. Interested in using pyrolysis in conjunction with other processes , and determining what plants thrive in the resulting product when added to local soils.

[fernpharao]

Dosis facit venenum! In Germany in Max-Planck-institute they found a way to control the biochar processing to a degree, where the output is biochar (as final product) as well as other products like some type of carbon-goo which could be processed to make gasoline and the producing of a kind of topsoil, without producing climate gas as its the case in the natural process of compost (of course good natural topsoil/humus/compost is more than this). On top of that, the processing is exothermic.

[snookmeister6]

In my comparison plantings, biochar led to a significant (100%) improvement in vegetable yields. I encourage gardeners to learn to make it and then apply it. Test it yourself and see if it makes a difference. I'm convinced and plan to continue using it. If you use sterile char alone and and expect to grow anything, you're likely to be disappointed. By all means, use compost, with and without char. See for yourself. Don't smoke your neighbors - learn smokeless methods. Cheers.

[Helioforge]

Just made a video on the properties of materials of charcoal for Terra Preta, a few days ago. If you look at it, please tell me if it misses anything important. It is of great interest to me to create a comprehensive visual teaching tool for Terra Preta.

Otherwise, people could potentially be led away from Terra Preta by not understanding that the material must first soak up tremendous amounts of mineral nutrients, and then allow microorganisms to find their natural balance within the soil.

[chrispecht]

Agricultural fires are everywhere on earth. The remaining ash has a much higher pH than biochar and it is often desired to increase the pH in agricultural soils. That is why lime is used in agriculture. Lime is very effective in increasing the pH.

[threeredstars]

i live in the mohave desert and for my soil so far, adding carbon has had a positive effect. the ph here is so high that adding the carbon brings the ph down but it also seems to make the soil hold moisture much longer. compost and carbon seems to work better but compost alone seems to dry out quickly.

[jeromnimooo1]

Compost and biochar don't have to be seen and used separatly. If you use biochar alone, no effect on crop will be observable (except at long term maybe, because of the enhance of microorganisms activity). It need nutrients. then the compost will bring nutrients and microorganism. The nutrients will be fixed and slowly released, and the microorganisms will reproduce in the pores.

[WoodsEndLaboratory]

Many people report better results when adding compost to biochar,- probably due to composts' very positive influences masking or ameliorating the harsh negative effects of the charcoal, which it is true are short lived- but enough to rule it out for most commercial farm operations. Factorial studies conducted by unbiased parties would have to be performed to determine if there is really any synergistic effect.

[clockguy2]

I live in an area with high rainfall and sandy soil. Nutrients wash through and out of the soil no matter how much humus I mix in. I am trying biochar and a no till method to see if it will hold the nutrients in place longer.

[Kotesu]

Thanks for the video, it's refreshing to see some critical thought in contrast to the hype: one question though... isn't the high pH a result how one produces biochar? I mean, they used to make lye and other alkalines by soaking wood ashes in water, didn't they? Is this effect reduced when a different methods of production are used (eg. higher temperatures during pyrolysis, soaking in urine or other acidic nutrient)? Have you done any tests in this regard?

[tigerone1970]

How about:

1) Adding biochar to compost or the compost pile? Say at 20%?

2) A high pH is highly beneficial for washed out soils, like tropical areas such as high veld sandy soils in Africa, or the Amazon rainforest. It is also beneficial for the takeup of Phosphorus and Potassium during the fruiting stages in such soils.

[ForestFront]

So, char will improve acid soils, but will have adverse effects on neutral or basic soils. Is this correct?

[WoodsEndLaboratory]

@ForestFront Yes- we think biochar functions as a strong cationic fertilizer (Ca, Mg, K) which will undoubtedly improve highly depleted soils but may be deleterious in under circumstances where flooding the CEC sites with more cations is obviously not desirable or agronomicaly responsible.-

[fm928]

Excellent work Dr. Brinton. I have also often wondered why anyone would use or produce biochar when compost provides many of the same carbon storage benefits, is great for plants and is already widely available at a relatively low cost.

Char is also biologically dead while compost is full of a diverse, active microbial community that can improve both plant and soil health.

[Pangolinx1]

@fm928 _ The answer is simple. Compost will burn off in a few years while biochar remains in the soil and continues to benefit. Repeated applications of compost with biochar accumulate benefit while repeated applications of compost alone will only reach equilibrium. The biomass to form the compost also has to come from outside your farmed area.

[onegreenday]

Hardwood biochar may be different than the biochar of the Brazil savana flood plain. They more likely used savana grass for biochar & may have had a different Ph.

Biochar is not a replacement for compost. Compost is also needed to build soils

[onegreenday]

I appreciate the critical look at terra preta biochar.

The char used in the Brazil amazon of terra preta fame most likely came from pyrolized savana grass of the flood plain and not hardwood lumps.

Perhaps their Ph was different than Woods Hole test.

Biochar is not meant to replace compost but to

supplement poor depleted soils and improve them.

It would be used in conjunction with compost.

[pflugelhorn]

No one is proposing to use large quantities of fossil energy to make biochar. It wouldn't be cost-effective.

The scientifically valid commercial biochar devices use small amounts of propane to start the pyrolysis, but the process then heats itself using the biogas emitted from the biomass.

[snookmeister6]

I've applied char to a test bed at a rate of 10% by weight . Thus far, the PH in the bed is below neutral. I'll soon plant spring vegetables and measure results compared to a control bed. I'll post the results. My char was produced entirely from urban waste - no fossil fuel was used in any way. Without question, a gardener should always be aware of soil PH and I agree about using scientific methods. It was fun making the char. I've had some spectacular gas fires.

good gardening

GT

[romedeiros70]

@WoodsEndLaboratory , I am curious: How many acres of land have you applied bio-char to in your studies? Char in truly biologically active soil should be different than char in a pot.

Your pile of compost would also produce negative results if used before it is aged, which means nature has a chance to balance it out. Did you give nature the same chance with char? Without that, this video seems premature as science.

[WoodsEndLaboratory]

@romedeiros70 The way agronomy and horticulture work as a body of science is that studies are performed in pots, in trays, in growth chambers and in field plots. Valid results reported objectively are not less science simply because they fail to please expectations. Other scientists are free to report other results.

[garyshouse305]

in your study you applied 25% biochar to the pot.this seems excessive which produced negative results. What would be the maximum amount of char applied to the soil in order to improve crop yields? 2%10%? before the test how much activated carbon was in in the soil?how does activated carbon or char improve soil conditions?does it help hold minerals in the soil or prevent leaching? does it give a place for soil bacteria to grow and thrive? does it hold moisture?

[WoodsEndLaboratory]

Biochar (if you watch our message to the density part) has about 1/5th the density of soil, which means 25% by vol is about 5% on a weight basis. Compost at that rate would push plants out of the soil and achieve great yield and soil benefit. Remember, it costs energy to spread soils .. if a product has no net benefit in the growing season in which it is applied, it may be better to put it somewhere else.

[bajarad]

This piece is an incomplete and inaccurate portrayal. Biochar can be a net source of non-fossil energy (not "fossil energy intensive" as claimed). Agronomic benefits of biochar have been documented in numerous studies (see IBI website).

Biochar is a diverse class of substances, properties of any given sample will depend on feedstock (source material) and specific kiln conditions (time and temperature).

Biochar can be complementary with compost, not a competing alternative.

[WoodsEndLaboratory]

We know of consultant's advocating soaking biochar in compost and manure which among others things does remove or obscure its harsh, short-term negative effects. Others advocate "pre-enegizing" (sic) biochar with nutrients,- same explanation. Once you step outside of real science and agronomy, anything you say about biochar seems credible.

[devanando]

Another inaccuracy is in the way the pH issue is presented. Many soils are acidic, and agricultural soils tend to become acidic over time. Biochar tends to have a liming effect, increasing the pH, but in many circumstances, this is positive.

It also should be noted that in tropical or arid regions, compost added to soil rapidly decomposes because of the heat and or moisture. Biochar is vastly more stable in these environments, and is a very good reason why one would chose biochar over compost.

[WoodsEndLaboratory]

That "Biochar tends to have a liming effect" may be a great understatement. It would be hard to locate soils in this region poor enough to benefit from biochar's harsh pH effect. With moderately carbon-rich soils that tend not to turn over rapidly, it is also difficult to imagine a benefit to adding more inactive carbon to them.

Rapid turnover of compost in warm climate soils is one of the great strengths of compost and a good reason to choose it to sustain yield and soil life.

[devanando]

There are a few inaccuracies I've noted in this video. One is that pyrolysis is a process that consumes fossil energy, and this isn't necessarily true at all. Properly engineered, pyrolysis is a self-sustaining exothermic process, and since it would cost significant amounts of money to drive the pyrolysis process with fossil fuels rather than recycle the excess heat generated, I doubt the industry will choose an inefficient, expensive approach, especially in light of rising fossil energy costs.

[josephdupont]

Compost causes Methane I think

and breaks down faster..

I love compost and put many tons of leaves into my garden every year. So why can t you just neutralized the carbon?

I like your video.. I seems to keep and open mind on the issue.

[TheCaptainLulz]

would it not make sense to put the biochar into an environment like an abandoned pit mine instead? it seems the commercial value is non-existant as it seems to be detrimantal to crops.

[WoodsEndLaboratory]

@TheCaptainLulz - I have thought this too, that it is not necessary to apply biochar to soil in order to justify carbon sequestration. But then the question is raised more strongly: why use biogenic materials that would otherwise benefit soil humus and microbes.

[TheCaptainLulz]

@WoodsEndLaboratory very true, alot of farmers where I live need this organic matter to keep the soil viable, everything else has been leached. and the problem doesn't change with biochar, its still fossil carbon thats causingthe problem. more than that, humus makes soils fertile allowing life to sequester the carbon into the soil. the humus therefore may have agreater sequestration potential over longer timespans than the char.

[jeffjohnvol]

Nice work, but regarding concerns of "carbon" in the environment, there is no conclusive evidence that CO2 causes global warming. Correlation does not prove cause and effect. Computer models are not evidence.

[ezkad]

amen

[IMBR549]

Thanks and nice work Will. There needs to be some common sense approaches to the benefits and uses of biochar. The technology folks are certainly going to need a home for the flood of material in the pipeline.