Terra Preta (Black Earth) is a fertile soil from the Amazon that stores nutrients and water better than usual soil. The black earth does not have to be bought because you can make it yourself using natural materials such as manure and manure.
What is Terra Preta?
Terra Preta refers to afertile “black earth” that can only be found in the South American tropics. The special thing is that it is not of natural origin. Thousands of years ago, indigenous people in the Amazon region prepared the barren, weathered soil using everyday waste products. Microorganisms decomposed the biomass and transported the nutrient-rich and water-holding substrate into deeper layers of the soil, where it still exists today as black soil.
This enabled the indigenous people to engage in profitable agriculture and thus consolidated the basis of their civilization in an inhospitable region. Scientific studies such as the “TerraBoGa” project at the Free University of Berlin confirm the yield-increasing effect of the carbon-containing Terra Preta on certain plants. It also sustainably supports the growth of local vegetables, fruit and ornamental plants in this country. The production of black earth is also simple.
Composition of Terra Preta
Today's analyzes show exactly what the Indians in Brazil used to prepare their soil. This composition had to compost or ferment in a certain mixing ratio for around eight weeks.
Components of Terra Preta in the Amazon region:
- Biochar
- Dung
- Compost
- Kitchen waste such as fish bones or animal bones
- Human feces
- pottery shards
Application of Terra Preta
In the garden and in (organic) agriculture, Terra Preta-type soil is used as aSoil additive in sandy soils that only have a thin layer of humus The carbon stores water and Nutrients like a sponge so that the soil is not washed out as quickly. In addition, nitrogen is bound better and increased aeration of the soil is ensured. Microorganisms also use the porous coal as a habitat. In larger numbers, they decompose more biomass into usable humus.
As a rule, sandy, nutrient-poor soils benefit best from Terra Preta-style soil. The storage function of coal is particularly beneficial for heavy eaters. You should therefore pay attention to the correct dosage when applying. The black soil you make or buy is worked into the soil or used directly as vegetable soil. Quantities for the application of Terra Preta are only guidelines and may vary depending on the source of information.
Heavy eaters like zucchinis benefit the most from Terra Preta.
Heavy feeders: Fast-growing heavy feeders can be recognized in large numbers by their large fruits. Typical representatives include tomatoes, most types of cabbage, potatoes, zucchini, pumpkin, cucumbers, celery, peppers and many more. About 20 liters of Terra Preta are applied to one square meter of bed area.
Medium feeder: Medium feeders are plants that lie between the two extremes. So they only grow moderately and produce only a few and/or small fruits. These include, for example, strawberries, carrots, onions, lettuce, radishes and beetroot. To supply them with enough nutrients, 10 liters of Terra Preta per square meter of bed is sufficient.
Weak feeders: Plants in this category like to grow in poor soil and in some cases even fix nitrogen in the soil. Pulses (legumes) such as beans, peas and lentils, but also radishes and many herbs are considered weak eaters. 5 liters of Terra Preta per square meter of bed area help to bind nitrogen so that the soil is sufficiently enriched with minerals in the crop rotation.
Make your own Terra Preta
The work required to make Terra Preta is small. There aretwo proven approaches Either you mix biochar etc. into your own compost regularly over the course of a year or you mix Terra Preta with existing, finished compost. The use of Effective Microorganisms (EM) in conjunction with Terra Preta is often recommended, but there is no evidence of effectiveness. For this reason, we will first look at EM in more detail in the next paragraph.
Effective microorganisms for producing Terra Preta?
A variety of degrading, building and neutral microorganisms live in the soil. While some consume air and produce nitrogen, the opposite applies to others. So they live in symbiosis and in balance. Problem: If the degrading microorganisms are present in too large a proportion, then they are said to damage the soil by promoting disease and rot. The addition of effective microorganisms (EM), on the other hand, is intended to ensure an excess of building microorganisms that promote growth conditions.
EM is also intended to improve compost quality, among other things. However, according to a study by the Agroscope Reckenholz-Tänikon (ART) research institute in 2007, a field trialfound “no effects that could be attributed to the microorganisms in the preparation [EM]”. Therefore, you may be able to avoid the expensive EM products. Instead, it is recommended to produce a manure to charge the compost mixture.
Variant 1: Make Terra Preta directly in the compost
The biochar and the primary rock powder are added to the compost.
When the new compost is made, it can be made directly the Terra Preta way without much effort. In addition,add some biochar and primary rock powder to each layer of compostThe biochar should have the European Biochar Certificate (EBC) - barbecue charcoal is not suitable. The primary rock powder must be silicate, lime-free and very fine (>10 micrometers); When you rub it, it should smear on your fingers. For every 1,000 liters of Terra Preta compost there are a total of 200 liters of biochar and 100 liters of primary rock powder. The quantities may vary depending on the source of information, as there is no one “correct” way of producing them.
Alternatively, you can also use the organic compost activator (€14.00 on Amazon) from Sonnenerde. It already contains the right ratio of biochar and primary rock powder and is available here. The application is identical. There are around three bags of activator for every 1,000 liters of compost.
Variant 2: Terra Preta from finished compost
You can subsequently convert existing compost into Terra Preta. But in order for the coal to soak up water and minerals, a waiting period of at least eight weeks is necessary. In theStep-by-step instructions we show you how to make Terra Preta with finished compost.
Instructions: Make your own Terra Preta with finished compost
Material for 100 liters of Terra Preta
- 10 liters of biochar
- 0.5 liters of plant manure or 1 liter of effective microorganisms
- 20 liters of animal manure
- 60 liters of compost
- 1, 5 kg silicate and fine rock powder (15kg / m³)
How to do it
- The biochar and animal manure are mixed well in a large bucket. A positive side effect of coal is that it binds unpleasant odors. It doesn't really matter which animal manure is used.
- EM or plant manure is added to the biochar-animal manure mixture.
- Compost comes into play next. This is mixed over a large area together with the mixture on a flat surface. The rock powder is also added. Then everything is mixed well and, if necessary, further diluted with EM or plant manure if the mixture is too dry.
- Cover the pile with a tarp; However, contact with the ground should remain. At night the temperature should not fall below 8 degrees Celsius. After about eight weeks, the tarpaulin can be removed and the Terra Preta can be used.
In the following video, Franz from the “keep it green” channel shows in detail how to make Terra Preta yourself using this method.
TERRA PRETA aus 5 ZUTATEN selber herstellen - Schritt für Schritt Anleitung?
Advantages and disadvantages of Terra Preta
Advantages of Terra Preta
- Stores nutrients so that they are more available to plants.
- Promotes the formation of mycorrhizae on the plant roots.
- The soil holds water longer, slowing down flushing.
- The pH value becomes more alkaline.
- Nitrogen binding is improved.
- Aeration of the soil is promoted.
- Overall he althier, more robust plants with higher yields.
- Heavy metals and pesticides are rendered harmless.
- C02 sink.
Disadvantages of Terra Preta
- Plants can absorb harmful polycyclic aromatic hydrocarbons (PAHs) via “bad” carbon.
- Purchased Terra Preta too expensive for large-scale use.
- Unsuitable for acid-loving plants (e.g. blueberries and rhododendrons). An acidic component must also be mixed in here.
- Not recommended as growing soil.
- Long-term effects on local soils unknown.
Criticism of Terra Preta
According to vegetable growing expert Marianne Scheu-Helgert from the Bavarian Garden Academy, your own compost, mulching and green manure are sufficient if the garden soil is already fertile. Jörg Hütter from the Demeter Association recognizes the advantages of Terra Preta, but criticizes the high prices for ready-made mixtures. And to what extent it actually makes sense to char biomass for Terra Preta instead of composting it or using it in the biogas plant, the scientific discourse has yet to show.
The 3 best sources
bionero
The Terra Preta soil from bionero comes 100% from Germany. In addition to wood, manure from the horse farm in the region comes into thein-house, modern pyrolysis systemFor this, bionero was nominated for the German Sustainability Prize in 2021, among other things. Accordingly, the biochar has the European Biochar Certification (EBC). On average, a 20-liter bag of humus-activated soil is enough for one square meter of bed area.
frux
The Terra Preta-style peat-free vegetable soil contains organically certified components, making the product suitable for organic gardens. The manufacturer states that due to the mix it should be used like regular soil. The ratio of biochar, natural clay, bark humus and compost is designed for immediate use in beds and buckets. So you can lift the 18 liter bag directly into the raised bed and distribute it over a large area. There's no easier way to get black soil into your garden
Carbo Verte
Black earth from Carbo Verte is also available as pure soil. However, depending on the needs of the plant (heavy, medium or weak feeder), the manufacturer recommends diluting the soilwith conventional soilAlternatively, the Terra Preta soil refined with primary rock powder can also be incorporated into existing beds. For this purpose, 2 kilograms of black earth are used per square meter of area. One bag contains 20 liters or around 12 kilograms of the sustainable soil additive.
Purchasing criteria
Whether Terra Preta or biochar will catch on in Germany or whether it will just be “hyped” remains to be seen. Many studies are currently underway, the results of which will determine the future of the soil improver. Until then, however, there is nothing to suggest conducting your own field trials on poor, sandy soils. To ensure that the purchase of finished products remains truly sustainable, you should pay attention to the composition of the earth and the origin of the coal.
Composition
From an ecological point of view, a good Terra Preta soil is peat-free. In addition, it should have a proportion ofat least 10 to 15% biochar and no more than 25%. The manufacturer should also indicate what products they used to treat the soil. It is best to contain regional biogenic residual products such as compost and horse manure. If the finished product also contains clay and rock powder among its components, then you have a good Terra Preta soil.
Origin
When purchasing, you should definitely make sure that the soil comes entirelyfrom German cultivation and domestic production. The origin of the coal is particularly important. If the source is not known, inferior charcoal may have been used, which may be harmful to he alth. An EBC or organic certificate ensures safe coal. Earth from traceable sources also contains no heavy metals or other pollutants. And the climate is happy about the short transport routes.
FAQ
What are the disadvantages of Terra Preta?
Terra Preta can be too alkaline for acid-loving plants. In addition, weak eaters do not feel comfortable in Terra Preta. With poor-quality coal, there is also the risk of releasing harmful components into the earth. Unfortunately, ready-made mixtures are also very expensive.
What are the benefits of Terra Preta?
Terra Preta is a soil additive that brings a we alth of benefits: improved plant growth by storing minerals, better aeration, binding of heavy metals and pesticides, high water storage capacities, habitat for microorganisms and increasing the pH value. The biochar in the Terra Preta is also a CO2 sink.
What does Terra Preta do?
Terra Preta is incorporated into the soil and fulfills a variety of tasks. First and foremost, it is a breeding ground for microorganisms that produce humus. In addition, minerals and water adhere to the porous surface. Due to its crumbly structure, it improves air supply.
How is Terra Preta made?
Terra Preta is added either during composting or afterwards with finished compost. In any case, biochar, primary rock powder and, if necessary, clay and/or animal manure are added to the compost. After a few weeks of rest, the soil can be worked into the bed in the Terra Preta style.
Is there criticism of Terra Preta?
It is very expensive to buy Terra Preta as a finished product. Furthermore, the long-term consequences of the large-scale use of Terra Preta are still unknown. It is not the miracle cure it is often made out to be. Because it is neither suitable as growing soil nor for acid-loving plants. Inferior coal in the black earth can also be harmful to he alth.
