Browns Fertilisers
"Qualified Agronomists, Quality Advice"

Mono-Ammonium Phosphate (MAP)

N% P% K% S% Zn% Other
Typical Analysis 10 21.9 0 1.5 0 1.6 Ca


Chemical Name
Mono ammonium phosphate
Crop Segments
Nitrogen and phosphorus present in every granule.
Quality & Handling
Nominal 2-4 mm granule sizing.
Bulk density 1.0 tonnes per cubic metre.
Blends with most other products.

1. Features

  • MAP is a high analysis source of phosphorus.
  • A cost effective granular product.
  • Low in heavy metals.
  • Good handling characteristics.
  • The nitrogen in MAP is in the ammonium form, which resists leaching and is a slower release form of nitrogen.
  • The product has an acid reaction in the soil which can be an advantage in neutral and high pH soils. Therefore MAP is used in preference to DAP on alkaline soils.

2. Manufacture

Ammonia gas is combined with phosphoric acid, granulated, dried and screened.

3. Uses

One of the major cropping fertilisers used in Australia as a source of phosphorus and nitrogen, MAP and MAP blends are used extensively in cropping systems and for sowing pastures. The low level of nitrogen makes it useful as a ‘starter’ fertiliser and as there is no free ammonia, the risk of affecting germinating seeds is minimal.

4. Storage and handling

  • Will store freely in shed storage for extended periods with little concern about moisture uptake.
  • Covering with a tarp will greatly  reduce any moist air uptake.
  • The use of augers may damage the fertiliser and increase any handling problems.
  • Do not leave exposed to moist air.
  • Either fill or empty (completely), the drill or air-seeder fertiliser box overnight.
  • Raise the equipment  tynes from the soil to stop moisture moving up the tubes.

5. Restrictions

  • For sowing there is little risk of affecting germination, even at high rates. As a general rule, a maximum of 20kg/ha of nitrogen at seeding of cereals should be used.
  • When applying MAP, the fertiliser should be banded 5cm away from the seed, either below or to the side. MAP is low in sulphur (1%). It is not recommended for high sulphur requiring crops such as canola, unless blended with sulphate of ammonia or other sulphur source.
  • Do not store in silos.