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Calcium nitrate

Also known as: Ca(NO₃)₂, Nitrate of lime

Calcium nitrate is a highly soluble fertilizer supplying nitrate-nitrogen together with a substantial readily available calcium content, widely used in fertigation and on crops where both rapid nitrogen uptake and calcium delivery to developing tissue are priorities.

Dated referenceLast reviewed: 2026-07-12Updated: 2026-07-12
Illustrative diagram · AgricultureID (original)

Calcium nitrate, Ca(NO₃)₂, is manufactured by reacting limestone or another calcium source with nitric acid. The resulting product typically analyses around 15.5% nitrogen, entirely as nitrate, together with about 19% calcium — one of the few fertilizers to deliver calcium in a rapidly soluble, readily plant-available form.

Because both the nitrate and the calcium it supplies are quickly available, calcium nitrate is commonly used where growers want fast-acting nitrogen alongside a calcium source that does not depend on soil dissolution, unlike carbonate-based liming materials.

Composition and analysis

Calcium nitrate is produced by neutralising nitric acid with a calcium source, typically limestone, yielding a highly soluble salt. Commercial grades commonly guarantee about 15.5% nitrogen, entirely in nitrate form, and roughly 19% calcium.

Chemical formula
Ca(NO₃)₂
Nitrogen content
About 15.5% total nitrogen, entirely as nitrate
Calcium content
About 19% calcium, in a rapidly soluble form
Physical form
Hygroscopic granules or prills; also sold as a liquid solution

Nutrients supplied

Calcium nitrate supplies nitrogen entirely as nitrate, available for immediate root uptake, and calcium in a soluble form that can move into the plant through the transpiration stream more readily than calcium from slower-dissolving sources such as ground limestone.

  • Nitrate portion is immediately plant-available
  • Calcium is supplied in soluble form, not requiring soil dissolution
  • Contains no phosphorus, potassium, or micronutrients

Use and benefits

Calcium nitrate is widely used in fertigation and hydroponic nutrient solutions, and on fruiting vegetables such as tomato and sweet pepper and on fruit crops such as apple, where adequate calcium supply to rapidly expanding tissue is a recognised management consideration alongside nitrogen supply.

  • Well suited to fertigation, hydroponics, and foliar programs due to full solubility
  • Used where both rapid nitrogen supply and soluble calcium delivery are wanted
  • Compatible with many liquid fertilizer blends when mixing compatibility is checked

Application principles

General practice is to apply calcium nitrate in split doses through the season, matched to nitrogen and calcium demand at key growth stages, and to check compatibility before tank-mixing with sulfate- or phosphate-containing fertilizers, since calcium can react with these to form insoluble precipitates.

Environmental considerations

As with other nitrate fertilizers, the nitrogen in calcium nitrate is mobile in soil and can be lost to leaching under heavy rainfall or over-irrigation, or to denitrification in saturated soils, so timing and rate management follow the same general principles as for other nitrate-nitrogen sources.

Relationships

Evidence-backed connections in the knowledge graph.

Supplies nutrients

Applied to crops

Related topics

Scope & limitations

Geographic scope: Global overview of calcium nitrate as a nitrogen and calcium fertilizer, common in fertigated, greenhouse, and high-value fruit and vegetable production.

Climate context: Nitrate leaching risk increases with high rainfall or irrigation volumes between applications and crop uptake, as with other nitrate-nitrogen sources.

  • This entry describes composition and general behaviour; it is not a nutrient rate recommendation for any crop or region.
  • Tank-mix compatibility with other fertilizers depends on the specific products involved and is not exhaustively covered here.
  • Calcium-related physiological disorders in crops have multiple contributing causes beyond nutrient supply, which this entry does not address.

Sources

This article draws on the following authoritative sources. See our sources & methodology for how they are selected.

  1. [1]FAO — Food and Agriculture Organization (opens in a new tab)

    Food and Agriculture Organization of the United Nations (FAO)

    Authoritative

    Cited for: Nitrogen and calcium fertilizer forms and use

    Type:
    Intergovernmental organization
    Jurisdiction:
    Global
    Accessed:
    2026-07-12
  2. [2]IFA — International Fertilizer Association (opens in a new tab)

    International Fertilizer Association (IFA)

    Moderate

    Cited for: Calcium nitrate product characteristics

    Type:
    Standards body
    Jurisdiction:
    Global
    Accessed:
    2026-07-12
  3. [3]USDA NRCS — Natural Resources Conservation Service (opens in a new tab)

    USDA Natural Resources Conservation Service (NRCS)

    Authoritative

    Cited for: Nitrate behaviour and calcium availability in soil

    Type:
    Government agency
    Jurisdiction:
    United States
    Accessed:
    2026-07-12
  4. [4]Cornell CALS — Plant pathology and crop resources (opens in a new tab)

    Cornell University College of Agriculture and Life Sciences

    High

    Cited for: Calcium nutrition in fruiting crops

    Type:
    University extension service
    Jurisdiction:
    United States (New York)
    Accessed:
    2026-07-12

Related topics

Plant Nutrients

Farming Systems

Irrigation