Today I started to ponder if any of the minerals in clay were left over after a firing. I wondered about this because the orchids I grow are epiphytes or lithophytes, and I grow them in ceramic pots and on ceramic mounts. This means they will attach their roots to the sides or outsides of mounts or pots.
As the clay pot starts to break down would the roots be able to extract nutrients? So…..I asked my new Ai friend Alex.
Good Afternoon Alex: When potters clay is fired do any of the minerals like NPK remain?
Alex: When pottery clay is fired in a kiln to create ceramic objects, the firing process typically involves high temperatures that can exceed 1000°C (1832°F) or more.
At these temperatures, any organic matter, including minerals like nitrogen (N), phosphorus (P), and potassium (K) – which are the main components of NPK fertilizers – are typically burned off completely during combustion.
As a result, the ceramic objects produced from fired pottery clay typically do not retain any significant levels of NPK or other nutrients.
However, the fired clay itself can still contain trace elements and minerals from its original composition, as well as any impurities or additives that may have been present in the raw clay. These trace elements are generally inert and do not contribute to nutrient availability in soil or plant.
Me: How about Silica? Does it remain? and what is its importance to plant nutrition?
Alex: Silica, also known as silicon dioxide (SiO2), is a mineral compound commonly found in clay and other types of soil.
When pottery clay is fired in a kiln to create ceramic objects, silica typically remains in the fired clay, as it is a highly stable compound that withstands high temperatures.
In terms of its importance to plant nutrients, silica itself is not considered a nutrient essential for plant growth. However, it plays a crucial role in supporting plant health and resilience in several ways:
- Structural Support: Silica can contribute to the structural integrity of plant cell walls, making them stronger and more resistant to physical damage from environmental stressors such as wind, pests, and disease.
- Drought Resistance: Plants that have sufficient silica levels tend to exhibit greater tolerance to drought stress. Silica helps to regulate water uptake and distribution within plant tissues, reducing the negative effects of water shortage on plant growth and development.
- Pest and Disease Resistance: Silica can act as a natural defense mechanism against pests and diseases. It forms a physical barrier on the surface of plant tissues, making them less palatable to herbivores and more difficult for pathogens to penetrate.
- Nutrient Uptake: While silica itself is not a nutrient, it can indirectly influence nutrient uptake and utilisation by plants. By improving root health and soil structure, silica enhances the plant’s ability to access and absorb essential nutrients from the soil.
Overall, while silica may not be considered essential for plant growth, its presence in soil and plant tissues can have significant benefits for plant health, resilience, and overall productivity.
Me: Could this be considered a plus for plants growing in fired clay pots? Would the roots have access to this silica in the fired pot?
Now Alex’s response here was less than optimum, in my opinion, it missed the fact that my orchids would be growing in soil-less conditions. I had to rephrase my question and ask was he talking about leaching of the silica? Alex continued to insist: Leaching of silica from the clay or ceramic material is less likely, as silica is a stable compound that remains bound within the structure of the pot or mount. Instead, the benefits of silica primarily stem from its influence on soil structure, root health, disease resistance, and water regulation within the growing medium.
So I asked: Yes but we are talking about growing with no medium at all.
Alex: I see, my apologies for the oversight. In the context of growing orchids without any medium, such as in soil-less clay pots or directly onto ceramic mounts, the indirect accessibility of silica becomes more nuanced. In this scenario, silica may still play a role in supporting orchid health and growth through the following mechanisms:
- Root Attachment and Stability: Even without a traditional growing medium, orchid roots may still come into contact with the surface of the clay pots or ceramic mounts. The presence of silica in these surfaces can provide a substrate for root attachment and stability, allowing orchids to anchor themselves securely and establish a foothold for growth.
- Moisture Regulation: Silica can help regulate moisture levels on the surface of clay pots or ceramic mounts by influencing water retention and evaporation. This can indirectly impact orchid hydration levels, helping to maintain a balanced moisture environment around the roots.
- Physical Protection: Silica can contribute to the durability and resilience of clay pots or ceramic mounts, providing protection against physical damage and environmental stressors. This enhanced structural integrity can indirectly support orchid health by reducing the risk of root injury or stress.
- Disease Resistance: While the direct contact between orchid roots and silica in this setup may be limited, the presence of silica in the pot or mount surface can still act as a barrier against soil-borne pathogens and pests. This may provide some level of protection against diseases and pests that could otherwise affect orchid health.
Overall, while the indirect accessibility of silica to orchid roots in a soil-less growing setup may be limited compared to traditional growing mediums, its presence in the surface of clay pots or ceramic mounts can still contribute to various aspects of orchid health and resilience.
Me: OK one more question please Alex?
Alex: Of course, feel free to ask! What would you like to know?
Me: Would there be anything else mineral or otherwise that would contribute to the orchids health in these growing conditions (soil-less) from the fired ceramic pot or mount?
Alex: In soil-less growing conditions, such as growing orchids directly on fired ceramic pots or mounts, the contribution of minerals or other substances from the ceramic material itself may be limited. However, there are a few factors to consider:
- Trace Elements: Fired ceramic materials can contain trace amounts of various elements and minerals, depending on the composition of the clay used and any glazes or finishes applied. While these trace elements may not directly supply nutrients to the orchids, they can potentially influence soil pH or other soil properties, which may indirectly affect plant health.
- Porosity and Aeration: The porosity of fired ceramic pots or mounts can influence air circulation and oxygen availability around the orchid roots. Adequate aeration of the root zone is essential for healthy root growth and nutrient uptake, so the porosity of the ceramic material can indirectly contribute to orchid health by promoting good root oxygenation.
- pH Stability: Fired ceramic materials are generally inert and stable, which means they are unlikely to significantly alter the pH of the growing environment. Maintaining a stable pH is important for nutrient availability and plant health, so the inert nature of ceramic pots or mounts can indirectly contribute to pH stability in soil-less growing conditions.
- Physical Support: Ceramic pots or mounts provide a stable and supportive structure for orchids to anchor themselves and grow. This physical support is essential for maintaining plant stability and preventing damage to delicate root systems, which can indirectly contribute to orchid health and growth.
Overall, while fired ceramic pots or mounts may not directly supply nutrients to orchids in soil-less growing conditions, they can still provide important benefits such as physical support, pH stability, and root zone aeration. Additionally, orchids grown in soil-less conditions may require supplemental fertilization or nutrient solutions to meet their nutritional needs effectively.
Me: OK thanks I think we wrote a great post here Alex!
Alex: You’re welcome! I’m glad I could help. It sounds like you have a fantastic post ready to go. If you ever need assistance with anything else or want to bounce around more ideas, feel free to reach out. Good luck with your post, and I’m here to help whenever you need me!
