The decision to use ammonium chloride is a decision about chloride. Every crop tolerates the ammonium; not every crop tolerates 66 % chloride by mass arriving with it. This page covers crop selection and field practice. The grade designation itself, and what the purity floor means, is defined on the agricultural grade page in the main fertilizer products section.
Substance identity
| Chemical name | Ammonium chloride |
| Synonyms | Sal ammoniac, muriate of ammonia |
| Formula | NH₄Cl |
| CAS | 12125-02-9 |
| Molar mass | 53.49 g/mol |
| Appearance | White to off-white crystalline solid or granules |
Specification
| Parameter | Value | Basis |
|---|---|---|
| Nitrogen (N) | ≥ 25.0–25.4 % | Typical commercial range |
| Nitrogen form | 100 % ammonium | Structural |
| Chloride, theoretical | 66.3 % | Calculated |
| NH₄Cl content | ≥ 94–96 % | Typical commercial range |
| Moisture | ≤ 0.5–1.0 % | Typical commercial range |
No application rates are given on this page. Rate depends on crop, yield target, soil test, residual nitrogen and local practice, and a general figure would be misleading rather than helpful.
Properties
Fully water-soluble at approximately 37 g per 100 g water at 20 °C, so the nitrogen becomes plant-available as soon as soil moisture is adequate — there is no slow-release character. Ammonium is exchange-held initially and nitrifies over subsequent weeks at a rate governed by soil temperature, moisture and aeration. Nitrification releases two protons per nitrogen atom and acidifies the root zone. Solution pH of the fertilizer itself is 4.5–6.0 at 5 %.
Applications
Well-suited — chloride-tolerant crops. Paddy rice is the principal case, and for a specific reason beyond tolerance: flooded soils are anaerobic, and sulfate applied in a sulfate-based ammonium fertilizer can be microbially reduced to sulfide, which damages rice roots. A chloride-based ammonium source does not introduce that risk. Coconut and oil palm, cotton and other fibre crops, sugar beet, barley and many cereals are also chloride-tolerant. In wheat, chloride application has been reported to reduce the severity of take-all and certain foliar diseases — a reported association, dependent on site and season, not a guaranteed effect and not a substitute for disease management.
Unsuitable — chloride-sensitive crops. Tobacco is the classic case, where chloride degrades burn quality. Potato, where tuber quality and specific gravity are affected. Grapevine, citrus, avocado, most stone fruit, beans and several berry crops. For these, choose a sulfate-, nitrate- or amide-based nitrogen source. On saline or sodic soils, and on soils with poor drainage where salts accumulate rather than leach, avoid it regardless of crop tolerance.
Practice. Because the nitrogen is entirely ammonium and initially exchange-held, incorporation or placement below the surface reduces losses relative to surface broadcast, particularly on soils of high pH where surface ammonium is vulnerable to volatilisation as ammonia. Split application over the season limits both salinity peaks and nitrate leaching after nitrification. Keep the fertilizer band away from the seed.
Handling and storage
Store dry and sealed. Never mix with lime, basic slag, calcium cyanamide or other alkaline amendments — the reaction releases ammonia gas and loses nitrogen. If liming is planned, separate the two applications in time. Keep clear of copper and steel equipment in humid conditions.
Notes
Plan liming as part of the programme, not as a reaction to a later soil test. Chloride can accumulate in soils with limited leaching, so on such sites monitor soil chloride rather than relying on crop tolerance alone. Where a soil is deficient in sulfur, note that this fertilizer supplies none and a separate sulfur source will be required.