Calcium ammonium nitrate

CAN is produced by blending ammonium nitrate with calcium carbonate (limestone or dolomite), typically yielding a granular product with about 27% total nitrogen, roughly split between ammonium and nitrate forms, plus a substantial calcium carbonate content.

Composition

Ammonium nitrate blended with calcium carbonate filler

Nitrogen content

About 27% total nitrogen, roughly half ammonium and half nitrate

Calcium content

Supplied as calcium carbonate, variable by formulation

Physical form

Granular, less hygroscopic than pure ammonium nitrate

CAN supplies nitrogen in both immediately available nitrate and more slowly nitrifying ammonium forms, and it contributes calcium, primarily through the carbonate filler rather than as a rapidly soluble calcium source.

• Nitrate portion is immediately plant-available
• Ammonium portion nitrifies over subsequent days to weeks
• Calcium carbonate contributes calcium and buffers acidity from nitrification

CAN is widely used in temperate cereal, root, and forage crop systems where growers want the dual-form nitrogen supply of ammonium nitrate together with a gentler effect on soil pH and improved granule handling.

• Combines quick and short-delay nitrogen availability in one product
• Milder soil acidification than straight ammonium nitrate over repeated use
• Improved storage and spreading properties from the carbonate filler

As with other nitrate-containing nitrogen fertilizers, general practice is to time and, where appropriate, split applications to match crop nitrogen demand and reduce the risk of nitrate leaching in wet periods.

The nitrate fraction of CAN is mobile in soil and subject to leaching losses on well-drained soils during periods of high rainfall or irrigation, and to denitrification under saturated conditions. Its acidifying effect on soil is generally milder than that of straight ammonium nitrate or ammonium sulfate.