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Chemical Elements to know

A Sulphur Crystal – source: Wikipedia


Here’s the short story of micro- and macro-nutrients you will come across in organic gardening books and videos.

Most of us didn’t really pay attention in the chemistry class unless we could let thing blow up! But for great success in gardening and farming it is necessary to know and understand a few of the elements found in the periodic table.

Macro nutrients and micro nutrients are categories of essential elements that plants need for their growth and development. The main difference between the two lies in the quantities required by plants and their relative importance for plant nutrition.

Macro nutrients are needed by plants in relatively large amounts. They are essential for the plant’s overall growth and development. On the other hand, micro nutrients, also known as trace elements, are needed in much smaller quantities, but they are equally important for various physiological and biochemical processes within the plant.

Note that chemical fertilizers and chemical pest control methods are not allowed in organic farming (see the reasons below) and you don’t want to poison yourself or your family and customers. There are a few chemical compounds allowed though in organic farming which we list below. Always consult the Namibian Organics Association though if you are unsure of what to use.

Here’s a list of both macro nutrients and micro nutrients:

Macro nutrients:

  1. Nitrogen (N): Helps in leaf and stem growth, as well as overall plant vigor.
  2. Phosphorus (P): Supports root development, flower and fruit production, and energy transfer.
  3. Potassium (K): Aids in water uptake, enzyme activation, and overall plant health.
  4. Calcium (Ca): Important for building strong cell walls and overall plant structure.
  5. Magnesium (Mg): An essential component of chlorophyll, necessary for photosynthesis.
  6. Sulfur (S): Supports protein synthesis and enzyme function.

Micro nutrients (Trace elements):

  1. Iron (Fe): Required for chlorophyll production and energy transfer.
  2. Manganese (Mn): Essential for enzyme activity and carbohydrate breakdown.
  3. Zinc (Zn): Necessary for hormone regulation and protein synthesis.
  4. Copper (Cu): Involved in chlorophyll formation and energy production.
  5. Boron (B): Supports cell division and carbohydrate transport.
  6. Molybdenum (Mo): Needed for nitrogen fixation in legumes.
  7. Chlorine (Cl): Important for osmotic balance and photosynthesis.
  8. Nickel (Ni): Required for certain enzyme functions.

Remember, while macro nutrients are needed in larger amounts, micro nutrients are equally critical for healthy plant growth, even though they are required in trace quantities. Ensuring a well-balanced supply of both macro and micro nutrients is essential for maintaining healthy and productive plants in organic gardens and permaculture farms.

Reasons to farm organically

Using organic fertilizers over chemical fertilizers offers several advantages, especially in the context of the global crisis associated with the excessive use of chemical fertilizers. Here are the reasons why organic fertilizers are a better choice:

1. Environmental Protection: Chemical fertilizers, when overused or mismanaged, can lead to nutrient runoff, polluting water bodies and causing algal blooms and dead zones. Organic fertilizers release nutrients slowly and improve soil structure, reducing the risk of water pollution and protecting aquatic ecosystems.

2. Soil Health: Organic fertilizers enhance soil health by promoting beneficial microorganisms and earthworms. They improve soil structure and water retention, reducing erosion and enhancing long-term fertility. Chemical fertilizers degrade soil quality, leading to a loss of biodiversity and fertile topsoil.

3. Reduced Greenhouse Gas Emissions: The production of chemical fertilizers is energy-intensive and releases greenhouse gases, contributing to climate change. Organic fertilizers, particularly those made on-site (e.g., compost), have a lower carbon footprint and help sequester carbon in the soil, mitigating climate change.

4. Sustainable Nutrient Management: Organic fertilizers are often made from renewable resources, such as compost, manure, and cover crops. This approach reduces the dependency on fossil fuels needed to produce chemical fertilizers and decreases the risk of resource depletion.

5. Biodiversity Conservation: Organic farming practices, including the use of organic fertilizers, encourage biodiversity by providing habitats for beneficial insects, birds, and other wildlife. Chemical fertilizers can harm beneficial organisms and contribute to habitat degradation.

6. Reduced Health Risks: Excessive use of chemical fertilizers can lead to residual chemical contamination in food, posing potential health risks for consumers. Organic fertilizers are safer, as they contain natural nutrients and do not leave harmful chemical residues.

7. Resilience to Climate Change: Organic farming practices, which include organic fertilizers, can improve soil’s water-holding capacity, making crops more resilient to droughts and extreme weather events associated with climate change.

8. Lower Dependency on Imported Inputs: In many cases, organic fertilizers can be produced locally on the farm, reducing the need for costly imported chemical fertilizers and fostering self-sufficiency.

9. Soil Fertility Maintenance: Organic fertilizers help maintain soil fertility in the long term by replenishing nutrients and organic matter, while chemical fertilizers can lead to nutrient imbalances and soil degradation over time.

10. Reasons we don’t understand yet. Most chemicals (especially in combination with others) have not properly been tested. And even if they have been deemed safe, we don’t know the long term consequences. Our world is a very complex system where we don’t come close to understanding it at all. With chemical fertilisers we risk creating catastrophic situations somewhere sometime. Why risk it?

In summary, transitioning to organic fertilizers can help address the global crisis associated with chemical fertilizer use. By promoting sustainable agriculture, protecting the environment, and preserving soil health, organic farming practices offer a more viable and responsible approach to feeding the growing global population while mitigating the impact of agricultural practices on the planet.

IFOAM permissable chemical compounds

Here’s a comprehensive list that includes the chemical elements, permissible forms, and application guidelines for their use in organic farming, based on the IFOAM guidelines or 2021. For up to date guidelines always check the IFOAM website:

  1. Nitrogen (N):
    • Permissible Form: Organic materials such as compost, manure, cover crops, leguminous plants.
    • Application Guidelines: Use organic nitrogen sources to promote healthy soil fertility and balance. Apply based on crop needs, timing, and incorporation methods.
  2. Phosphorus (P):
    • Permissible Form: Rock phosphate, bone meal, guano, fish meal.
    • Application Guidelines: Apply based on soil tests and crop requirements. Incorporate into soil before planting or side-dress during the growing season.
  3. Potassium (K):
    • Permissible Form: Potassium sulfate, kelp meal, wood ash.
    • Application Guidelines: Spread evenly across the field and incorporate into soil. Apply based on crop needs and soil tests.
  4. Calcium (Ca):
    • Permissible Form: Lime, gypsum.
    • Application Guidelines: Use to adjust soil pH and provide calcium to plants. Apply based on soil test results and pH targets.
  5. Magnesium (Mg):
    • Permissible Form: Epsom salt (magnesium sulfate).
    • Application Guidelines: Apply based on soil tests and crop requirements. Can be applied as a foliar spray or incorporated into soil.
  6. Sulfur (S):
    • Permissible Form: Elemental sulfur, sulfur-based compounds.
    • Application Guidelines: Apply for disease control and nutrient availability. Follow recommended rates and timings.
  7. Boron (B):
    • Permissible Form: Borax, other natural boron-containing materials.
    • Application Guidelines: Use to address boron deficiency. Avoid excessive use to prevent toxicity.
  8. Copper (Cu):
    • Permissible Form: Copper oxychloride, copper hydroxide, copper sulfate, copper-based mixtures.
    • Copper oxychloride is a copper salt and allowed as a crop protectant up to 6kg Cu per ha per year. This as per the IFOAM Norms of 2014 which are the standards according to which we certified in Namibia.
  9. Iron (Fe):
    • Permissible Form: Chelated iron compounds.
    • Application Guidelines: Apply to address iron deficiency. Adjust rates based on soil and crop conditions.
  10. Manganese (Mn):
    • Permissible Form: Manganese sulfate.
    • Application Guidelines: Use to correct manganese deficiencies. Apply based on soil tests and crop needs.
  11. Molybdenum (Mo):
    • Permissible Form: Naturally occurring molybdenum compounds.
    • Application Guidelines: Provide if deficiency is suspected. Monitor soil tests.
  12. Zinc (Zn):
    • Permissible Form: Zinc sulfate.
    • Application Guidelines: Apply to address zinc deficiency. Follow recommended rates and methods.

Remember that the availability of these elements can vary based on soil types and conditions, so it’s essential to tailor your application practices to your specific farming context. Always contact the Namibian Organics Association to ensure you adhere to local organic farming guidelines and consult with experts for the most accurate and up-to-date information.

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