Bara clay

The natural and unique plateau clay for horticulture substrates


During the last Ice Age, a wonderful clay was uniquely created in the southern part of Sweden. This clay is remarkable since it is formed on hills, not in valleys like most other clays, hence its name – Plateau Clay.

Due to the height at which it is extracted, the clay has never been in contact with groundwater. Throughout the millennia of rain, lime, chloride and sodium sulphides have been washed out and only the stable (favourable) minerals remain. Bara Clay is clean with extremely low levels of heavy metals, making it highly suitable for professional horticulture.

Bara Clay naturally contains the correct mineral composition, with recordable trace and micro elements, that plants (roots) favour. Bara Clay is 100% natural with no added minerals.


A substrate with high Water Uptake Capacity is important for the grower. A substrate should absorb water quickly and evenly, in order to optimize the irrigation time. A substrate that has a strongly hydrophobic peat surface often has problems with long irrigation times and uneven distribution of moisture. The high content of illite and smectite minerals in Bara Clay cover the peat surface, making the substrate strongly hydrophilous. This means that substrates mixed with Bara Clay absorb water quickly and evenly. A substrate with Bara Clay makes a big difference to the Water Uptake Characteristic (WOK), see the diagram.
WOK 600X400


A high Cation Exchange Capacity in the substrate benefits the grower because it keeps nutrients in the substrate for a longer period of time and nutrients do not wash out. In outdoor production, as much as a third of the nutrients can be washed out of the pots. Having a substrate with high Cation Exchange Capabilities makes the substrate highly flexible in distributing the nutrients. Three-layer clay with clay minerals of smectite and illite as in Bara Clay have a high Cation Exchange Capacity in substrates, see the diagram. nts do not wash out.
CEC 600X400


A substrate with high Anion Exchange Capacity is as important as a high CEC. A substrate with high AEC has a high P-buffering capacity that makes a difference to the uptake of phosphorus. Growers have found that this supports and increases the plants’ root system and plant tissue. Easily mobile phosphorus is often washed out of the substrate, which is detrimental for both the plants and the environment. The unique Bara Clay has the right mineral compositionfor high buffering. With Bara Clay in the substrate, the P-buffering capacity can increase by up to 60-70 %, see the diagram.
AEC 600X400


Using Bara Clay in the potting soil is an effective method to buffer fertilizers. Adding Bara Clay to the substrate makes it possible to avoid leaching of fertilizers, and the grower also gains flexibility in fertilizer management. The percentage indicates the buffering of major elements in solution with Bara Clay. In addition to buffering cations (+), there is clear buffering of anions (-). Because of the buffering the EC will be flattened by 30-40 %. At higher doses of fertilizer or in the accidental release of (coated) fertilizers, Bara Clay will prevent too high EC in the root environment. The buffered ions in the clay complex remain available for the plant and do not wash out.
Bara Mineraler Managing Fertilizing'


It is known that a high CEC is important. What the CEC value doesn’t tell us, however, is what ions and at what proportions the various cations and anions are fixated into the clay complex. The CEC of Bara Clay is mainly formed by Ca2+, Mg2+ and K+ in the right proportions. Professional growers know that ions such as K+, Ca2+, Mg2+, NH4+, NO3-, SO4 2- and PO4 3- are necessary for the plants. It is important that these ions are specifically those taken up by the clay in the substrate and given back to the plant root when  needed. It is therefore essential to be certain that the clay mineral is mainly occupied by Ca2+, Mg2+, K+, in the right proportions and not by other ions, e.g. Na+. Bara Clay contains a high content of clay minerals (particles lutum <2μm), combined with a high and good balance between cations and anions. This is the important value for a high-quality, useful horticultural clay.
Bara Mineraler Yield


In potting soils with peat substitutes such as coconut, wood fibre and bark, the buffer capacity of nutrients decreases. These materials have a lower buffer and naturally have a higher pH value to start with. Due to the lack of peat, the ability to add lime is limited. Less liming means a smaller buffer against acidification.  Mixtures with little peat and in which no lime is left are more sensitive to pH drops under the influence of fertilization and the growth of plants. The Bara Ca Plus clay has an excellent buffering capacity and a stabilizing  effect on the pH during the growth period.


All life on earth needs at least 60 minerals to function. A person does not feel well if they are short of just one mineral and nor does a plant. Such unhealthy plants attract diseases and pests, and therefore disease pressure is constantly increasing and yields are lower. By using fertilizer we only give back 10-15 minerals, while we harvest 60 minerals from the soil. As a result, our soils lack various minerals. Trace elements (e.g. iron, manganese, nickel, zinc, molybdenum, boron) are only needed in very small quantities in the plant, but are nevertheless essential for its growth. If one is missing, they will no longer function properly. In addition, plants need micro-elements such as selenium,  silicon and strontium. Bara Clay is a naturally clean clay that is rich in trace elements and microelements that can be absorbed by the plant.
Blomma 600X400


A prosperous soil contains thousands of species of bacteria, fungi, unicellular animals, nematodes, worms, and insects, which regulate several crucial processes. A healthy soil is indispensable for the development and growth of strong, healthy plants. Healthy plants are less susceptible to diseases, pests, and stress, which means that they can also absorb nutrients and grow optimally. Two factors are extra important for a healthy and prosperous soil: Mycorrhizal fungi and favourable soil bacteria. Most substrates for professional growers are based on peat, which is usually more or less sterile. By adding Bara Clay to the peat, the micro-life in the substrate increases and improves. This is one of the reasons why nurseries and plantations in greenhouses, not only in Sweden but around the whole of Europe, mix Bara Clay into their substrates. Bara Clay promotes the formation of micro-life in the soil. On the one hand, Bara Clay contains natural and valuable soil bacteria, for example nitrogen-fixing bacteria such as Azotobacter, which assimilates nitrogen from the air, and phosphorus-releasing bacteria. But perhaps, the most important property is that Bara Clay, with its rich and well-balanced content of minerals, is an incredibly good catalyst that benefits and quickly initiates a growth of the micro-life in a substrate. This has been shown in several experiments with, among others, mycorrhizal fungi.
Lera Rot 600X400


Bara Clay can be used excellently to bind (glue) peat for making sturdy plugs. With the disappearance of German black peat, manufacturers are looking for alternatives. The available alternatives mostly consist of younger (white) peat from the Baltic countries. In recent years we have built up a lot of experience in gluing all kind of substrates with different types of peat. The Bara Clay used for this purpose is the composition of clay fractions specifically tailored to the type of peat. Bara Clay is also a valuable addition to growing plugs on water.


When you buy Bara Clay, you are buying real clay minerals! The clay content (lutum <2μm) of Bara Clay  granules is very high. The percentage of sand particles is very low. Bara Clay has a unique composition of mostly 3-layer clay minerals such as illite and smectite. These 3-layer clay minerals produce a high internal surface with a high buffer capacity. Due to field drying, covered storage and heat treatment, the moisture percentage on delivery is only 2-3%. The low moisture percentage and the high content of clay minerals provide value for money.
Clay Products 600X400


RHP CERTIFIED Bara Clay has been RHP certified since 1998. Bara Clay is heated to 80°C. It is safe, dry and easy to handle, easy to distribute in the peat. FiBL CERTIFIED Bara Clay is certified by FiBL, the Research Institute of Organic Agriculture. This means Bara Clay can be used in organic cultivation in the Netherlands with SKAL certification.


For precise dosage recommendations, the type of culture, pot size, peat fraction, irrigation and fertilizer management must be considered.
Bara Mineraler Dosage

Successful plant cultivation in Billeberga

The most important thing for Stefan is that the substrate is airy and maintains its structure, easily and quickly absorbs water, and buffers nutrients to minimize nutrient leakage. The cultivation substrate consists of both block peat and harrow peat with the addition of 40 kg Bara clay per cubic meter.
Bara Mineraler Lera Ingla Blommor Highres 2897