Ammonium sulphate

Overview

Two nutrients in a 50 kg bag: nitrogen and sulphur. It supplies both together, which matters because a crop short of sulphur cannot make full use of the nitrogen you give it. Its nitrogen is in the ammonium form, which produces some acidity as it converts in the soil — useful around the fertiliser band on high-pH land, though on calcareous ground the free lime neutralises most of it. It is a nutrient, not a spray for pests or disease.

Composition

Ammonium sulphate

Type

Micro Nutrients · Nutrient

Chemical group

Nitrogen + sulphur fertiliser

Pack size

50 kg

Controls

Recommended crops

Mode of action

Promotes healthy plant growth, green leaves, and helps correct Sulphur deficiency.
Best use: Useful where soils are deficient in nitrogen and/or Sulphur.
Suitable crops: Can be used for vegetables, fruit crops, cereals, and other crops according to crop requirements.
Special feature: Can help lower soil pH, making it particularly useful in alkaline soils.

Dose & application

Apply according to the crop, soil condition, and nutrient requirement. Soil testing and agricultural recommendations should be followed.

Application: Apply to the soil near the plant and irrigate after application. Avoid placing large amounts directly against seeds or plant stems.
Dose: Apply according to the crop, soil condition, and nutrient requirement. Soil testing and agricultural recommendations should be followed.
Caution: Avoid excessive application, as too much nitrogen can cause excessive vegetative growth and nutrient imbalance.
Storage: Store in a dry, cool place and protect from moisture.
Safety: Wear gloves when handling fertilizer, avoid contact with eyes and mouth, and wash hands after use.

Why it pays

Two nutrients in one bag, and the second is the one that gets forgotten. Sulphur has been running down in Pakistani soils as the older fertilisers that carried it were replaced by high-analysis ones that do not. On oilseeds and brassicas, which have a high sulphur demand, it is often the nutrient actually limiting the crop. On other crops a poor response to nitrogen has many possible causes — leaching, waterlogging, drought, weeds, or simply too little applied — so confirm sulphur is the shortage before buying for that reason.

Field tips

It is not a bag-for-bag swap for urea: a 50 kg bag of urea carries roughly twice the nitrogen, so matching it sack for sack under-feeds the crop. What this bag earns its place on is the sulphur alongside the nitrogen. Split the application rather than putting it all in at once, because nitrogen leaches on light land. And it is not the answer for salt-affected ground — that is gypsum's job where the land is sodic.

Safety

A bagged soil fertiliser. Keep it dry, because it cakes. Wear gloves while handling and wash afterwards. Nothing here is sprayed and there is no pre-harvest interval. Store away from feed and drinking water.