The Nutritional Code of Plant Growth: Macronutrients, Secondary Nutrients & Micronutrients

Nutrient elements play a crucial role in the growth and development of plants. There are 17 essential nutrients required for plant growth, and based on the amount needed, they are classified into macronutrients, secondary (medium) nutrients, and micronutrients.

1. Macronutrients

• Macronutrients include carbon, hydrogen, oxygen, nitrogen, phosphorus, and potassium. Among them, nitrogen (N), phosphorus (P), and potassium (K) are widely known as the three primary fertilizer elements.

• Nitrogen: A key component of proteins and nucleic acids. Deficiency results in pale or yellow leaves (especially older ones), stunted growth, and poor fruit development. Excess nitrogen causes overly lush green foliage, excessive elongation, lodging, and reduced drought and pest resistance — and may even hinder fruiting.

• Phosphorus: Involved in energy transfer and genetic material synthesis. Deficiency causes dark green or purplish leaves, stunted plants, and inhibited development. Excess phosphorus can lead to deficiencies in other elements like iron and zinc.

• Potassium: Regulates physiological functions and improves stress resistance. Deficiency results in yellowing and browning of leaf edges on older leaves, reduced fruit quality and yield. Excess potassium can lead to calcium and magnesium deficiencies.

2. Secondary (Medium) Nutrients

• Calcium (Ca), magnesium (Mg), and sulfur (S) fall into this category.

• Calcium: Crucial for cell wall formation and structural stability. Deficiency leads to poor growth at shoot tips and can cause issues like blossom end rot in tomatoes. Excess calcium can induce potassium and magnesium deficiencies.

• Magnesium: Central to the chlorophyll molecule. Deficiency first appears in older leaves as interveinal chlorosis and can spread to young leaves, affecting fruit development. While plants tolerate magnesium well, imbalances with K and Ca can affect growth.

• Sulfur: Participates in protein synthesis and various metabolic processes. Deficiency starts in young leaves, causing yellowing (similar to nitrogen deficiency, but starts in new leaves). Excess can lead to premature leaf drop.

3. Micronutrients

• Includes iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), molybdenum (Mo), boron (B), nickel (Ni), and chlorine (Cl).

• Iron: Involved in photosynthesis and respiration. Deficiency leads to interveinal yellowing in young leaves, progressing to a pale white appearance while veins remain green. Excess iron may cause toxicity, browning of leaves, and inhibited root growth.

• Copper: Important in redox reactions. Deficiency results in malformed or chlorotic leaves; in grasses, shoot tips may wither. Excess copper can suppress root growth and cause root tips to thicken and become brittle.

• Zinc: Vital for auxin synthesis and enzyme activity. Deficiency results in stunted growth, shortened internodes, small clustered leaves, and “little leaf disease” in fruit trees. Excess zinc may cause chlorosis and interfere with iron and manganese uptake.

• Manganese: Supports photosynthesis and nitrogen metabolism. Deficiency causes interveinal chlorosis and mottling, progressing to necrosis. Excess manganese causes brown spots on older leaves and inhibits uptake of other elements.

The Importance of Balanced Nutrition in Modern Agriculture

With the increasing demand for high yields, excessive application of NPK fertilizers has become common. However, this has led to:

• Soil degradation from prolonged overuse of macronutrients

• Worsening deficiencies in micronutrients

Applying secondary and micronutrient fertilizers offers several significant benefits:

✅ 1. Boosting Crop Yields

For fields long reliant on macronutrient fertilizers, targeted use of micronutrients can significantly improve yields — particularly in medium- and low-yield areas — and help maintain productivity in high-yield fields.

✅ 2. Improving Crop Quality

Secondary and micronutrient fertilizers enhance the nutrient balance, improving not only yield but also quality — for example, by lowering nitrate levels in produce and preventing nutrient-deficiency-related diseases.

✅ 3. Increasing Fertilizer Efficiency

According to Liebig’s Law of the Minimum, a lack of any nutrient can limit growth. Supplementing with secondary and micronutrients helps balance nutrient ratios, maximizing uptake and minimizing waste.

✅ 4. Reducing Pests and Diseases

Balanced nutrient supply strengthens resistance to disease, drought, heat, and cold. For instance, applying boron promotes sugar transport, forms boron-sugar complexes that acidify cell sap, and inhibit pathogen development.

✅ 5. Protecting the Environment

Better nutrient absorption reduces fertilizer runoff, minimizing environmental pollution and contributing to sustainable agriculture.

🌿 Our Fertilizer Product Range

To meet the diverse nutritional needs of plants, we offer a full range of high-quality fertilizers:

Macronutrient Fertilizers

• MKP (00-52-34)

• MAP (12-61-00)

• DAP (21-53-00)

• UP (17-44-00)

• SOP (00-00-50, 00-00-52)

• NOP (13-00-45, 13-00-46)

  These provide essential nitrogen, phosphorus, and potassium.

Secondary Nutrient Fertilizers

• CAN (Calcium Ammonium Nitrate)

• CAL-MAG (Calcium Magnesium Fertilizer)

• AS (Ammonium Sulfate)

• Magnesium Sulfate

  These replenish calcium, magnesium, and sulfur for optimal physiological function.

Micronutrient Fertilizers

• Boric Acid, DOT (Disodium Octaborate Tetrahydrate)

• Manganese Sulfate, Zinc Sulfate, Ferrous Sulfate

• EDTA-CuNa₂ (Copper Chelate)

• EDTA-FeNa (Iron Chelate)

• EDTA-ZnNa₂ (Zinc Chelate)

• EDTA-MgNa₂ (Magnesium Chelate)

  All designed for targeted correction of micronutrient deficiencies.

📌 Application Methods and Dosage Highlights

Macronutrients

• Commonly applied as water-soluble fertilizers via foliar spray, seed soaking, or fertigation (sprinkler/drip systems).

• Standard dosage: 8–10 kg per acre, adjusted by crop type, growth stage, and soil fertility.

• For fertigation: dilute twice and apply 3–5g in planting holes, mixed with soil to avoid root burn.

Secondary Nutrients

• Often applied as base fertilizer before sowing or transplanting, or side/top dressing based on deficiency symptoms.

• Acidic, swampy, and sandy soils are more prone to magnesium deficiency.

• Dosage: 5–10 kg per acre per application, adjusted based on soil tests and crop needs.

Micronutrients

• Applied via foliar spray, seed soaking, seed coating, or root dipping.

• As usage amounts are small, overdosing can be harmful.

• Example: Boron — 0.5–1 kg/acre as base fertilizer; 0.1%–0.3% solution for foliar spraying.

  
  

  Zinc Sulfate — 1–2 kg/acre as base fertilizer; 2–6 g per kg of seed for coating.

In Summary

Understanding the roles of macronutrients, secondary nutrients, and micronutrients — and applying them scientifically and appropriately — not only promotes healthy plant growth and improves yield and quality, but also contributes to sustainable agricultural development and environmental protection.