Biochar: Envi­ron­ment­ally friendly and versa­tile

“A healthy soil contains up to ten percent humus. Today it is usually only two to three percent” (Fredy Abächerli, Mana­ging Director of Verora GmbH and inst­ructor for soil struc­ture, humus manage­ment and compos­ting).

An intact humus layer stores nutri­ents and water as well as large amounts of the green­house gas CO₂. Biochar faci­li­tates this process. With a surface of 200-500 m² per gram and a high poro­sity, biochar can absorb up to five times its own weight in water and the nutri­ents contained in it. The “green carbon” remains stable during decom­po­si­tion and does not rot.

As a result, farmers can improve the quality of soil with biochar, save money for ferti­li­sers and obtain addi­tional credits from emis­sion certi­fi­cates.

Further advan­tages:

• Less stench
• Nitrate loads in soil and ground­water are consi­der­ably reduced
• The forma­tion of climate-dama­ging gases is consi­der­ably reduced
• Soil acidi­fi­ca­tion is reduced
• Humus build-up is increased
• Plant nutri­ents remain avail­able much longer
• The need for addi­tional ferti­liser is signi­fi­cantly reduced

The use of biochar has multiple advan­tages in the vineyard: It loosens the garden soil and makes it perme­able to water and oxygen. Important micro­or­ga­nisms can settle in the soil, demons­trably impro­ving soil ferti­lity. Thanks to its huge surface area and high poro­sity, biochar also has an excel­lent capa­city to store nutri­ents and water. There­fore, the ability of the grape­vines to with­stand extreme weather condi­tions such as weeks of drought stress and subse­quent flood-like rain­fall is signi­fi­cantly improved.

Biochar has also proven to be an envi­ron­ment­ally friendly and effec­tive carrier of manure. Biochar reduces nutrient leaching and envi­ron­ment­ally harmful emis­sions. Last but not least, the use of biochar in the vineyard is an important contri­bu­tion to climate protec­tion: carbon is returned to the soil from the CO2-conta­mi­nated atmo­s­phere.

Biochar can signi­fi­cantly improve the biogas yield. This is firstly due to the proper­ties of biochar, which binds impu­ri­ties thanks to its porous struc­ture and large surface area and thus stabi­lises the biogas process. In addi­tion, the substrates in the fermenter can be broken down more effec­tively because the micro­or­ga­nisms in the biochar matrix are better protected.

Biochar also has a number of advan­tages for the biogas process when it comes to climate protec­tion. If biochar is added to the fermen­ta­tion residue, nutrient losses and climate-dama­ging methane gas losses are reduced. If the fermen­ta­tion residue is carbo­nised, high-quality biochar can be produced from it and the carbon contained in the fermen­ta­tion residue is bound over the long term. This not only protects the envi­ron­ment, but also substan­ti­ally improves the effi­ci­ency of the gas produc­tion process.

In Europe, 90% of biochar is first used in animal husbandry (see Joachim Gerlach, Ithaka Journal 1/2012). Biochar is used in silage, as animal feed, in litter, for manure treat­ment or as a compost addi­tive.  Biochar improves animal health, reduces unplea­sant odours, opti­mises the quality of ferti­liser and reduces losses of nutri­ents that are harmful to the climate and the envi­ron­ment.

Guaran­teed quality: European Quality Label EBC

This is precisely why coal for animal feed is subject to strict quality control. It must be free of toxins, in parti­cular all tar subs­tances and their deri­va­tives must be comple­tely expelled. Last but not least, heavy metals are unde­s­i­rable in animal feed, which is why the raw mate­rial must also be care­fully selected. In order to define a quality stan­dard, the European Biochar Certi­fi­cate (EBC) was estab­lished, which sets the stan­dards for high-quality biochar.

Highly sustainable: Casca­ding use of biochar

The casca­ding use of biochar in animal husbandry and ferti­liser manage­ment, where the adsorp­tion capa­city of biochar plays an outstan­ding role, is also inte­res­ting from an economic point of view.

Stage 1: Silage

At the begin­ning, biochar is added to the silage, which prevents the forma­tion of myco­to­xins. At the same time, pesti­cides are fixed and the forma­tion of butyric acid is prevented, resul­ting in cleaner fermen­ta­tion and a noti­ce­able impro­ve­ment in feed quality.

Stage 2: Diges­tive process

The biochar then enters the feed via the silage, enhan­cing diges­tion of the animals. The feed intake is increased, which results in an increase in weight. This also reduces the forma­tion of green­house gases.

Stage 3: Stable hygiene

Biochar is added to the litter, thus binding the liquid nutri­ents and redu­cing ammonia emis­sions. It helps prevent putre­fac­tion, which in turn improves stable hygiene. After just a few days, unplea­sant odours are noti­ce­ably reduced. What’s more, stables do not have to be mucked out so often, thus saving time and mate­rial.

Stage 4: Liquid manure

Biochar can also be mixed into the liquid manure, which binds vola­tile nutri­ents and improves the micro­bial envi­ron­ment. This reduces nutrient losses, which improves the ferti­li­zing effect of the liquid manure. In addi­tion, the liquid manure becomes almost odour­less.

Stage 5: Farm­land

After absorp­tion of the manure (solid-liquid sepa­ra­tion), the solids are composted toge­ther with the stable bedding, which produces valu­able black earth thanks to the high propor­tion of biochar. The incor­po­ra­tion of this black soil and the stabi­lised liquid manure into the soil improves the water reten­tion capa­city, the filter perfor­mance and the aera­tion of the soil, which results in higher ferti­lity. Soil acidi­fi­ca­tion is prevented and the leaching of ferti­li­sers and pesti­cides into ground­water is reduced.

The advan­tages at a glance:

• Improved health and increased vita­lity of the animals
• Increased feed effi­ci­ency
• Increase in feed intake
• Increase in weight
• Streng­t­he­ning of the immune system
• Increase in milk quality in cows due to improved udder health
• Reduc­tion of diar­rhoea and diseases of the hooves and footpad
• Increase in egg produc­tion and egg quality in poultry
• Impro­ve­ment of meat quality
• Decrease in morta­lity rate
• Signi­fi­cant increase in milk ingre­dients
• Improved stable hygiene and reduced odour pollu­tion
• Enor­mous odour reduc­tion of the liquid manure
• Reduc­tion of costs for medi­cines and vete­ri­na­rians

The possible uses of biochar (pyro­ly­ti­cally produced biomass carbon) are extre­mely varied. It also has nume­rous posi­tive effects when used in indus­trial processes. Mainly in the form of activated carbon (adsor­bent) in water, gas and air puri­fi­ca­tion, but also as a redu­cing agent in metall­ur­gical processes, activated biochar has great poten­tial. In the cement industry, biochar can be used as an additive/replacer as well as in the produc­tion of buil­ding mate­rials.

Last but not least, biochar is bene­fi­cial because it substi­tutes fossil fuels and thus improves the CO₂ foot­print (for more reading: Weber 2016, Biokohle. Herstel­lung, Eigen­schaften und Verwen­dung von Biomas­se­kar­bo­ni­saten, p. 279–282 [German]).