CNT & CAN: The ‘Calcium-Nitrogen Duo’ from Farmland to Industry

Nitrate compounds are indispensable nutrient sources in modern agriculture, providing efficient nitrogen for crops while regulating soil pH and promoting root development. From common potassium nitrate to specialized magnesium nitrate formulations, these compounds play a critical role in enhancing crop stress resistance and quality.

This article focuses on two typical calcium nitrate - based fertilizers—Calcium Nitrate Tetrahydrate (CNT) and Calcium Ammonium Nitrate (CAN)—comparing them in production processes, compositional properties, and agricultural applications to help readers scientifically select the most suitable fertilizer.

I. Production Processes: From Ore to Fertilizer—A Chemical Journey

Calcium Nitrate Tetrahydrate (CNT)

CNT is produced using limestone or calcite as raw materials. The process involves dissolving these materials in nitric acid to form a calcium nitrate solution, which is then crystallized and dried to create white crystals containing four water molecules (tetrahydrate).

• Core Reaction:

  
  

   CaCO₃ + 2HNO₃ → Ca(NO₃)₂ + CO₂↑ + H₂O

  
  

• Temperature (60–80°C) and nitric acid concentration (40%–50%) are strictly controlled to ensure product purity.

  
  

Calcium Ammonium Nitrate (CAN)

CAN is manufactured via a "composite method," blending ammonium nitrate solution with calcium nitrate or limestone, followed by neutralization, evaporation, and granulation.

• Typical Formula: 5Ca(NO₃)₂·NH₄NO₃·10H₂O

  
  

• The nitrogen - to - calcium ratio (typically N:Ca = 14:21) is precisely regulated, and anti - caking agents are added to enhance stability. High - end CAN products may also include trace elements like boron or zinc to meet specific crop needs.

II. Composition and Properties: The Science of Calcium - Nitrogen Ratios

Indicator	Calcium Nitrate Tetrahydrate (CNT)	Calcium Ammonium Nitrate (CAN)
Chemical Formula	Ca(NO₃)₂·4H₂O	5Ca(NO₃)₂·NH₄NO₃·10H₂O
CAS No.	13477 - 34 - 4	15245 - 12 - 2
Nitrogen Content	11.8% (nitrate - N)	14%–26% (nitrate - N + ammonium - N)
Calcium Content (as CaO)	19%	21%
Water Solubility	100% soluble, highly hygroscopic	100% soluble, better anti - caking than CNT
pH Value	Neutral to slightly acidic (5.5–6.5)	Neutral to weakly alkaline (6.5–7.5)
Stability	Prone to decomposition at high temperatures, requires moisture - proof storage	Stable at room temperature, suitable for long - term storage

Key Differences:

• Nitrogen Form: CNT contains only nitrate nitrogen, ideal for crops needing rapid nitrogen supplementation; CAN combines nitrate and ammonium nitrogen (1:1 ratio), offering prolonged nutrient release.

  
  

• Calcium Availability: CNT has higher water - soluble calcium (23.7%), making it suitable for foliar spraying; CAN’s calcium bonds more stably with nitrate, ideal for soil base application.

  
  

• Soil Adaptability: CAN’s weak alkalinity neutralizes acidic soils, while CNT performs better in neutral or slightly acidic soils.

III. Diverse Application Fields: Cross-Industry Value from Farmland to Industry

1.Agricultural Applications: Fertilization Operation Guide

Soil Testing and Fertilization Plan Formulation

•Soil Testing: Before fertilization, conduct soil testing to analyze pH value, organic matter content, and nutrient levels (nitrogen, phosphorus, potassium, calcium, etc.).

• Acidic Soils (pH < 5.5): Prioritize CAN. Its weak alkalinity neutralizes soil acidity while supplying calcium.

• Neutral/Alkaline Soils (pH 6.5–8.0): CNT is more suitable to avoid calcium precipitation in high-pH environments.

Suitable Crop Types

Calcium Nitrate Tetrahydrate (CNT)

o Fruits & Vegetables: Solanaceous crops like tomatoes and cucumbers (prevents blossom end rot).

o Commercial Crops: Calcium-demanding fruit trees such as grapes and citrus (foliar spraying enhances fruit firmness and sugar content).

Calcium Ammonium Nitrate (CAN)

o Leafy Greens: Nitrogen-sensitive crops like cabbage and spinach (promotes leaf growth).

o Field Crops: Grasses like wheat and corn (strengthens stalks to reduce lodging).

Application Methods for Calcium Nitrate Tetrahydrate (CNT)

• Base Fertilization:

  
  

   o Timing: 7–10 days before sowing or transplanting.

  
  

   o Method: Spread evenly on the soil surface and incorporate via plowing.

  
  

   o Rate: 110–220 pounds per acre, based on crop calcium demand and soil calcium levels.

  
  

• Topdressing:

  
  

   o Timing: Mid-crop growth stage (e.g., fruit expansion).

  
  

   o Method: Drip irrigation or flush application (dissolve and apply with water).

  
  

   o Concentration: Solution concentration controlled at 0.1%–0.2%.

  
  

• Foliar Spraying:

  
  

   o Timing: Early fruit expansion, 2–3 times every 7–10 days.

  
  

   o Method: Dilute 1000–1500 times and spray evenly on leaves and fruits.

  
  

   o Precautions: Avoid spraying in high heat or strong sunlight to prevent leaf burn.

  
  

Application Methods for Calcium Ammonium Nitrate (CAN)

• Base Fertilization:

  
  

   o Timing: Before sowing or transplanting.

  
  

   o Method: Spread evenly and mix into soil via plowing.

  
  

   o Rate: 176–265 pounds per acre, based on crop nitrogen demand and soil nitrogen levels.

  
  

• Topdressing:

  
  

   o Timing: Rapid growth stages (e.g., jointing in wheat, heading in corn).

  
  

   o Method: Band or hole application near crop rows/roots, followed by soil covering.

  
  

   o Rate: 88–132 pounds per acre, adjusted for crop growth.

  
  

• Precautions:

  
  

   o Environment: Avoid fertilizing before/after rain to minimize nutrient runoff.

  
  

   o Mixing: Can be blended with organic fertilizers to improve soil structure and fertilizer efficiency.

  
  

Comprehensive Fertilization Recommendations

• By Crop Type:

  
  

   o Fruits & Vegetables (e.g., tomatoes, cucumbers): Use CNT for foliar spraying to prevent physiological diseases and improve fruit quality.

  
  

   o Field Crops (e.g., wheat, corn): Combine CAN for base and topdressing to meet nitrogen and calcium needs.

  
  

• By Soil Type:

  
  

   o Acidic Soils: Choose CAN to neutralize soil acidity.

  
  

   o Neutral/Slightly Alkaline Soils: Choose CNT to avoid calcium precipitation in high-pH conditions.

  
  

• By Fertilization Technique:

  
  

   o Drip Fertilization: Ideal for CNT, ensuring water-efficient nutrient delivery.

  
  

   o Mechanical Fertilization: Suited for CAN, compatible with large-scale machinery for efficiency.

  
  

2. Industrial and Specialized Applications

Calcium Nitrate Tetrahydrate (CNT)

• Concrete Early Strength Agent:In construction, CNT acts as an early strength agent, accelerating cement hydration, shortening setting time, and enhancing early-stage strength (e.g., adding 0.5%–1% CNT during winter construction increases 3-day concrete strength by 20%–30%). Its water-soluble calcium and nitrate ions synergize to improve the bonding performance of cementitious materials.

  
  

• Pyrotechnics and Explosive Raw Material:As an oxidizer, CNT is used in manufacturing fireworks and signal flares, providing oxygen for combustion and imparting specific flame colors (e.g., calcium ions produce brick-red flames). It partially replaces traditional oxidizers in low-sensitivity explosive formulations to enhance safety.

  
  

• Wastewater Treatment:In industrial wastewater treatment, CNT adjusts water pH and serves as a calcium source, forming calcium phosphate precipitates with phosphate ions to remove phosphorus pollutants.

  
  

Calcium Ammonium Nitrate (CAN)

• Intermediate for Compound Fertilizers:As a nitrogen-calcium composite raw material, CAN is widely used in producing high-concentration water-soluble and foliar fertilizers, especially in drip irrigation systems where it is blended with trace elements to meet precise fertilization needs.

  
  

• Metal Surface Treatment:In steel pickling or electroplating processes, CAN acts as a corrosion inhibitor. Its nitrate ions form a protective film on metal surfaces, reducing excessive erosion by acid solutions (e.g., adding 1%–2% CAN during steel pipe pickling extends equipment lifespan by 15%).

  
  

• Mining and Blasting:In open-pit mining and tunnel engineering, CAN serves as an oxidizer component in emulsion explosives, replacing part of ammonium nitrate to reduce hygroscopicity and caking risks, thereby improving blasting stability.

IV. CAN Formulation Innovations: From Basic to Customized

1. Diverse Nitrogen Content

• Low - Nitrogen (N=14%–15%): Predominantly nitrate nitrogen, suitable for low - nitrogen crops (e.g., legumes) or base fertilization.

  
  

• Medium - Nitrogen (N=20%–21%): Balanced nitrate and ammonium nitrogen, ideal for topdressing leafy greens and grasses.

  
  

• High - Nitrogen (N=26%–27%): Higher ammonium nitrogen for prolonged release, suited for long - season crops (e.g., sugarcane, corn).

  
  

2. Trace Element Enrichment

• CAN+Boron: Contains ≥0.5% boron to promote flowering and fruiting, perfect for boron - dependent crops like rapeseed and cotton.

  
  

• CAN+Magnesium: 3:1 calcium - magnesium ratio, addressing magnesium - deficient soils (e.g., preventing banana yellow leaf disease).

  
  

• CAN+Sulfur: 3%–5% sulfur content improves soil aeration, suitable for cruciferous crops.

  
  

3. Process Optimization

• Tower Granulation: Produces spherical particles with 40% higher crush strength and 30% faster solubility, ideal for mechanized application.

  
  

• Anti - Caking Coating: Paraffin/resin coating extends shelf life to over 2 years, reducing transportation loss.

V. Our Calcium-Nitrogen Product Portfolio: Full-Spectrum Nutrient Solutions

Calcium Nitrate Tetrahydrate (CNT):

Expert in Efficient Calcium Supplementation & Diverse Applications

As a high-purity calcium-nitrogen compound, CNT serves as a dual-effect solution for rapid nitrogen supplementation and precise calcium application:

• Agricultural Applications:

o Fruit & Vegetable Quality Enhancement: Foliar spraying during tomato fruit expansion or grape color change stages (diluted 1000–1500 times) effectively prevents blossom end rot and fruit cracking, while improving fruit firmness and sugar content. Drip irrigation at 0.1%–0.2% concentration rapidly supplies water-soluble calcium (23.7%), ideal for calcium-demanding crops like cucumbers and citrus in neutral/alkaline soils.

• Industrial Innovations:

o Concrete Early Strength Agent: As an eco-friendly additive, 0.5%–1% dosage accelerates cement hydration, increasing concrete strength by 20%–30% within 3 days—especially suitable for winter construction and precast component production.

o Wastewater Treatment: By forming calcium phosphate precipitates with phosphate ions, it achieves ≥90% total phosphorus removal in electroplating and chemical wastewater, helping meet strict environmental compliance standards.

Calcium Ammonium Nitrate (CAN):

Optimal for Long-Acting Nitrogen-Calcium & Soil Amendment

CAN excels in acidic soils and field crops:

• Agricultural Advantages:o Field Crop Protection: Band/hole application during wheat jointing or corn tasseling stages extends nitrogen release by 15–20 days, enhancing stalk lodging resistance. Basal application in acidic soils neutralizes acidity (pH increased by 0.5–0.8), improving root development conditions.

• Industrial Value:o Core Raw Material for Compound Fertilizers: High-stability granules are ideal for formulating drip/foliar fertilizers, synergizing with magnesium, boron, and other elements to meet precise nutrient demands in (water-fertilizer integration) systems.

o Metal Surface Protection: Adding 1%–2% during steel pickling forms a dense oxide film, reducing acid erosion and extending equipment lifespan by over 15%.

Additional Product Portfolio: Tailored to Diverse Needs

• Anhydrous Calcium Nitrate (Anhydrous CNT):o With purity ≥99% and no crystalline water, it’s specially designed for soilless cultivation and premium water-soluble fertilizers, ensuring stable nutrient solution concentration and balanced calcium-nitrogen uptake for elevated crops like strawberries and blueberries.

• Cal-Mag (Calcium-Magnesium Complex):o Featuring a 3:1 Ca:Mg ratio, it rapidly corrects magnesium deficiencies (e.g., banana yellow leaf disease, grape vein chlorosis), promoting chlorophyll synthesis and increasing photosynthetic efficiency by over 20%—suitable for acidic red soils in southern China.

• CAN+Boron (Boron-Enriched):o Containing ≥0.5% boron, this ternary blend of N-Ca-B enhances pod-setting rates by 25% in rapeseed and cotton when sprayed during flowering. Basal application in apple orchards reduces misshapen fruits, improving fruit uniformity by 30% and addressing the issue of “flowering without fruiting.”

Conclusion

Calcium Nitrate Tetrahydrate (CNT) and Calcium Ammonium Nitrate (CAN), through scientific compositional design and process innovation, not only balance high crop yields with soil health in agriculture but also demonstrate cross-industry value in industrial manufacturing, environmental protection, and beyond.

From farmland to factory, and from basic fertilization to customized solutions, these "calcium-nitrogen powerhouses" deliver precise nutrient support across diverse scenarios through their diverse functionalities.

We remain committed to advancing sustainable development with high-quality products, empowering our clients to achieve a win-win between efficient production and ecological conservation.