Calcium Nitrate Tetrahydrate (15.5-0-0 + 19% CaO) is a fully water-soluble, chloride-free fertilizer that delivers two essential nutrients in immediately available forms. With 15.5% nitrate nitrogen and 19% water-soluble calcium oxide, this crystalline product provides rapid nitrogen uptake for vigorous growth while supplying calcium to strengthen cell walls, prevent physiological disorders, and improve soil structure. It is the preferred choice for greenhouse vegetables, fruit trees, and any crop where quality, shelf life, and stress resistance are critical.

I. Scientific Advantages

Dual Nutrient Power in One Crystal
Calcium nitrate tetrahydrate contains 15.5% nitrogen entirely in the nitrate form. Nitrate-N is taken up directly by plant roots without any microbial conversion, making it instantly available even in cold or acidic soils. The 19% calcium oxide (equivalent to 14% actual calcium) is fully water-soluble and immediately plant-available.

Chloride-Free and Low Salt Index
Unlike many potassium or calcium sources, calcium nitrate contains no chloride. This makes it safe for chloride-sensitive crops such as tobacco, citrus, berries, lettuce, and many ornamentals. Its low salt index allows high application rates without risk of root burn.

pH Buffering for Better Nutrient Uptake
When dissolved in irrigation water, calcium nitrate produces a slightly alkaline solution but, when taken up by plants, the nitrate anion has a base effect, helping to counteract acidity in the root zone. In fertigation systems, it helps maintain a stable pH range (6.0–6.5) when combined with acidic fertilizers.

Enhances Uptake of Other Nutrients
Calcium improves root membrane integrity, which enhances the selective uptake of potassium, magnesium, and micronutrients. Adequate calcium also reduces the incidence of blossom-end rot in tomatoes and peppers, bitter pit in apples, and tip burn in lettuce.

II. Key Agronomic Benefits

Immediate Nitrogen for Fast Growth
Because all nitrogen is in the nitrate form, plants green up quickly after application. This is especially valuable in early spring, after transplanting, or when recovering from stress. Nitrate nitrogen also does not acidify soil as much as ammonium- or urea-based fertilizers.

Stronger Cell Walls for Better Quality
Calcium is a critical component of the middle lamella, the “glue” that holds plant cells together. Adequate calcium results in firmer fruits, less cracking, longer shelf life, and better resistance to fungal diseases. In leafy vegetables, calcium prevents tip burn and internal necrosis.

Improved Soil Structure
The calcium in calcium nitrate flocculates clay particles, creating a crumb structure that improves water infiltration, aeration, and root penetration. This is particularly beneficial in heavy clay or compacted soils.

Reduced Physiological Disorders
Many common crop disorders are directly related to calcium deficiency: blossom-end rot (tomato, pepper, eggplant), bitter pit (apple), cork spot (pear), internal browning (celery), and empty pod (peanut). Regular supply of soluble calcium from calcium nitrate largely prevents these problems.

III. Application Methods and Recommendations

Fertigation (Drip and Sprinkler Systems)

• Rate: 50–150 kg per hectare per application, depending on crop and growth stage.
• Typical schedule: apply 10–20 kg per hectare every 2–5 days during peak demand.
• Concentration: 0.5–1.5 grams per liter of irrigation water.
• Compatibility: Mix with potassium nitrate, magnesium sulfate, and micronutrients. Do not mix with phosphates or sulfates in concentrated stock solutions (precipitation risk). Inject calcium nitrate through a separate tank.

Foliar Spray

• Concentration: 0.5–1.0% (500–1000 g per 100 liters of water).
• Timing: Apply at fruit set, during rapid fruit enlargement, and pre-harvest for quality improvement.
• Frequency: 2–4 applications spaced 10–14 days apart.
• Additive: Use a non-ionic surfactant for better leaf coverage.
• Response: Fruit firmness improves within days; shelf life extends significantly.

Soil Application (Pre-Plant or Side-Dress)

• Rate: 200–400 kg per hectare broadcast and incorporated before planting.
• Side-dress: 100–200 kg per hectare during early fruit development.
• Benefit: Provides both nitrogen and calcium deep in the root zone, especially effective in sandy or low-calcium soils.

Hydroponic Nutrient Solutions

• Target concentrations: 150–200 ppm nitrogen (as nitrate), 100–150 ppm calcium.
• Use calcium nitrate as the sole source of both calcium and nitrate in most formulas.
• Maintain pH at 5.8–6.2 after mixing; calcium nitrate helps buffer against pH drops.

Seedling and Transplant Production

• In propagation media: Apply 0.5–1.0 g per liter of water every third watering.
• Soilless mixes: Use a starter solution containing calcium nitrate (50 ppm N) to promote root development and avoid damping‑off.

IV. Technical Specifications

Chemical Properties

• Formula: Ca(NO₃)₂·4H₂O
• Total nitrogen (N): 15.5% minimum (all nitrate form)
• Calcium oxide (CaO): 19.0% minimum (actual Ca: 14%)
• Molecular weight: 236.15 g/mol
• Solubility: 1400 g/L at 20°C (extremely high)
• pH of 1% solution: 6.5–7.5 (neutral to slightly alkaline)

Physical Properties

• Appearance: White, translucent granules or small crystals
• Bulk density: 900–1100 kg/m³
• Particle size: 2–4 mm (granular), 0.5–2 mm (crystalline), fine powder available
• Moisture: ≤ 0.5%
• Hygroscopicity: moderate; store in sealed bags

Quality Standards

• Purity: ≥ 99.0%
• Heavy metals: Cd ≤ 1 ppm, Pb ≤ 2 ppm, As ≤ 1 ppm, Hg ≤ 0.1 ppm
• Chloride (Cl): ≤ 0.01%
• Insoluble matter: ≤ 0.05%

Available Grades

• Agricultural Grade: For soil, fertigation, and foliar use.
• Greenhouse Grade: High purity, low heavy metals, fully soluble.
• Hydroponic Grade: Ultra‑low chloride (< 0.005%) and heavy metals.

V. Crop‑Specific Recommendations

Tomatoes, Peppers, and Eggplants

• Prevention of blossom-end rot: Begin fertigation with calcium nitrate at first flower (10–15 kg/ha per week) and continue through fruit set.
• Foliar sprays: 0.5–1% at fruit set and again 10 days later.
• Results: Firm, glossy fruit, extended harvest, and storage life doubled.

Apples, Pears, and Stone Fruits

• Pre‑bloom: 200–300 kg/ha broadcast; calcium moves slowly in trees, so early application is key.
• Post‑bloom: Two foliar sprays of 0.7–1% one month and two weeks before harvest.
• Reduces bitter pit, cork spot, and storage scald. Fruit firmness after 6 months storage improved by 30%.

Lettuce, Celery, Cabbage

• Fertigation: 5–10 kg/ha every 3–4 days after transplanting.
• Foliar spray at 0.5% if tip burn appears.
• Prevents marginal leaf necrosis and internal browning.

Strawberries and Berries

• Drip application: 10–15 kg/ha per week from flowering through harvest.
• Calcium boosts fruit firmness, reduces mold, and improves transportability.

Potatoes

• At tuber initiation and bulking: 100–150 kg/ha calcium nitrate.
• Reduces internal brown spot, hollow heart, and increases specific gravity.

Cotton

• At squaring and boll development: 100–200 kg/ha broadcast or through irrigation.
• Improves boll size, fiber length, and reduces boll rot.

Ornamentals and Turf

• For roses and flowering plants: Fertigate at 5–10 g per square meter per month.
• Turf: Calcium nitrate at 20 g/m² as a spring green‑up gives rapid response without acidifying the soil.

VI. Compatibility and Mixing Guidelines

Compatible with

• Potassium nitrate (KNO₃)
• Magnesium sulfate (MgSO₄)
• All chelated micronutrients (Fe, Zn, Mn, Cu, B, Mo)
• Most water‑soluble fertilizers that are not high in phosphates or sulfates in concentrated form.

Incompatible with

• Concentrated phosphate solutions (MAP, MKP, DAP) – forms calcium phosphate precipitate.
• Concentrated sulfate solutions (e.g., gypsum, ammonium sulfate) – forms calcium sulfate (gypsum) precipitate.
• Alkaline materials (lime, caustic soda) – can cause ammonia release if mixed with ammonium salts.

Tank Mixing Order for Fertigation
Always prepare two separate stock tanks: one for calcium nitrate and one for all other fertilizers (especially phosphates). Inject the two solutions into the irrigation mainline on different sides of the water source, or inject them sequentially with a water flush in between.

For Foliar Tank Mix
Fill tank with water, add calcium nitrate first, stir until dissolved, then add other compatible products (e.g., potassium nitrate, micronutrients). Do not add phosphates. Use immediately.

VII. Environmental and Safety Profile

Soil and Water
Calcium nitrate does not contribute to long‑term soil acidification; indeed, it can help raise pH in very acidic soils. Nitrate is subject to leaching in sandy soils, so split applications are recommended. The product is chlorine‑free and has low heavy metal content, making it environmentally safe when used as directed.

Safety Precautions
Calcium nitrate is classified as an oxidizing agent (UN 1454). Keep away from organic materials, fuels, and reducing agents. In case of fire, use large quantities of water. Avoid inhaling dust. Wear gloves, goggles, and dust mask when handling. In case of eye contact, flush with water; if ingested, drink water and seek medical advice.

Storage
Store in original sealed bags in a cool, dry, well‑ventilated area, away from combustibles. Keep bags off concrete floors to prevent moisture wicking. Shelf life: 24 months.

VIII. Quality Assurance and Certifications

Our calcium nitrate tetrahydrate is produced in ISO 9001:2015 and ISO 14001:2015 certified facilities. Each batch is tested for nitrogen content, calcium, chloride, heavy metals, and solubility. We provide Certificates of Analysis with every shipment. OMRI‑listed and organic‑compliant grades are available.

IX. Why Choose Our Calcium Nitrate Tetrahydrate

Exceptional Purity
We guarantee 15.5–0–0 + 19% CaO with chloride below 0.01%, making it safe for the most sensitive greenhouse crops.

Rapid and Complete Dissolution
Our fine‑crystalline grade dissolves in less than one minute in cold water, leaving no precipitate. Granular grade is designed for soil application and blending.

Technical Support
Our agronomy team provides fertigation schedules, tank mix compatibility testing, and disorder diagnosis (e.g., blossom-end rot, bitter pit) to help you get the most from your calcium nitrate program.

Flexible Supply
Available in 25 kg moisture‑proof bags, 1‑ton FIBCs, and bulk containers. Custom anti‑caking treatment optional.

X. Ordering and Contact Information

Product Availability

• Granular grade for soil (2–4 mm)
• Crystalline grade for fertigation and foliar (0.5–2 mm)
• Fine powder for hydroponics and custom blends