Biochar is obtained from vegetable raw materials and is very porous. The basis for the production can be twigs and branches of hedge, tree or grass cuttings. On the other hand, other vegetable raw materials such as grain husks and cellulose fibers can also be used for the production.
Biochar is produced by a process known as pyrolysis. For this purpose, the organic raw materials are heated at a temperature of between 500 and 600° Celsius and broken down into their solid and gaseous components under oxygen extraction. This process is either carried out in a specially lined hole in the ground or in a special oven called a „Kon-Tiki“. If the production is done professionally, it is done in special industrial plants.
However, the principle of production is the same in all cases. By removing the oxygen and the high temperature, the organic materials are slowly charred. This can be thought of as similar to barbecue charcoal, but it should not be mixed up or confused in any way. Neither can be used as fertilizer in its raw state. When wood chars, it can even release toxic carbon compounds as well as dioxins.
What are the disadvantages of Biochar? Explanation, meaning, definition
Especially when used improperly, the disadvantages of Biochar can be particularly effective. It can also be fatal to work with bad charcoal from the beginning. Biochar works in much the same way as a rechargeable battery. Nutrients are absorbed and retained in it. Plants can then use it as needed. If the Biochar is enriched with nutrients before use, the battery is recharged, so to speak.
Anyone who simply puts Biochar into the soil without first enriching it with nutrients risks fatal consequences for the soil. The Biochar then takes its nutrients from the soil. These nutrients are then only secondarily available to the actual plant. Although in all probability the plant will recover from this in the next season, in the short term you are at a disadvantage for the time being. To avoid this disadvantage, the Biochar can be provided with a certain fertilizer before use in the home garden, so that it receives sufficient nutrients.
Another disadvantage of Biochar can be if you have a very good and nutrient-rich soil at home. So it can happen that the Biochar does not show any effect at all, but rather acts like humus. Although this is not a big disadvantage, but you will not notice any particular changes.
Since the Biochar is very stable, it also remains in the soil for a long time. However, if you resort to low-quality or even polluted charcoal, you risk serious problems for your plants. Since Biochar is mainly made from raw materials, it may also be contaminated with some pollutants. These, in turn, can cause problems when some plants are consumed. In some cases, the Biochar can also bind these substances itself, which can sometimes solve the problem on its own. Those who produce the Biochar themselves may find that the ash content is too high. The ash has a very high pH, which can be harmful to some plants.
So, if one wants to experiment with Biochar, it is crucial to enrich the charcoal with microorganisms and nutrients before using it. Failing to do so, farmers and gardeners experience exactly the reverse effect. The Biochar will take all the nutrients around it from the soil and store them. Therefore, pure Biochar should not be applied directly to the field or garden. Even small amounts of Biochar can cause exactly the opposite effect.