CAN Calcium Nitrate
Calcium Ammonium Nitrate (CAN) combines fast-acting nitrate nitrogen with calcium for cell wall strength. Prevents blossom end rot in tomatoes and tip burn in lettuce, while delivering immediately available nitrogen without the volatilisation risk of Urea.
How to Use
Top-Dress Application
Apply 150–200 kg/ha as a top-dress at 3–4 week intervals during vegetative and fruiting stages. Broadcast evenly between crop rows and incorporate lightly into the soil surface. Unlike Urea, CAN does not volatilise — it can be applied on a dry surface if rain is expected within 48 hours.
Fertigation (Drip Irrigation)
Dissolve 1–2 kg per 100 litres of irrigation water. CAN dissolves readily with minimal agitation. Inject into the drip system during the last 30 minutes of an irrigation cycle so it is washed into the root zone by the final flush of clean water.
Calcium Deficiency Treatment
For tomatoes showing blossom end rot (dark sunken patch at the fruit base), apply CAN as a soil drench (500 g dissolved in 10 L of water per 10 m²) and repeat weekly for 3 weeks. Also reduce irrigation stress — calcium uptake is linked to consistent water supply.
Foliar Calcium Spray
Dissolve 200 g per 10 litres of water for a foliar calcium spray. Apply directly to developing fruits and growing tips every 10 days during fruiting. Spray in the early morning — calcium is most readily absorbed through young tissue.
Timing for Best Results
CAN nitrogen is primarily in the nitrate form (NO₃⁻) — immediately available to plants without any soil conversion step. This makes it especially effective in cool soils where urea conversion is slow, and in mature crops that need a fast nitrogen response.
Storage
CAN is highly hygroscopic — absorbs moisture rapidly and sets into a hard mass if exposed to humid air. Store in sealed bags in a dry location. If granules have caked together, break them up before applying to ensure even distribution. Shelf life: 12 months in sealed storage.
Key Features
Prevents Blossom End Rot
Calcium strengthens cell walls in developing fruit. Regular CAN applications prevent the calcium deficiency that causes blossom end rot in tomatoes, peppers, and aubergine.
Instant Nitrate Nitrogen
NO₃⁻ is taken up directly by roots without soil conversion — faster plant response than Urea or ammonium sources, especially in cold or waterlogged soils.
Low Volatilisation Risk
Unlike Urea, CAN does not release ammonia gas on the soil surface. Can be surface-applied before rain without significant nitrogen loss — more forgiving in field conditions.
Fertigation Compatible
Fully soluble — dissolves cleanly in irrigation water for drip and sprinkler fertigation systems. Does not block emitters or nozzles.
Improves Produce Quality
Adequate calcium improves shelf life of harvested produce — firmer tomatoes, crisper lettuce, longer post-harvest life for export markets.
Safe Near Seedlings
Lower ammonia risk compared to Urea or DAP makes CAN safer for application closer to young, sensitive seedlings at transplant.
Tips & Nutrient Management
- Do not mix CAN with phosphate fertilisers (DAP, TSP) in the same tank — calcium reacts with phosphate to form insoluble calcium phosphate that blocks drip emitters and wastes both fertilisers.
- In alkaline soils (pH > 7.5), CAN's slightly alkaline reaction can reduce iron and manganese availability — watch for interveinal chlorosis (yellow leaves with green veins) and apply a foliar micronutrient spray if needed.
- For maize and sorghum, CAN is an excellent alternative to Urea for top-dressing in late-season applications where slow Urea conversion would miss the crop's nitrogen demand peak.
- Store separately from ammonium nitrate fertilisers — mixtures can become explosive if contaminated with fuel or organic material (a serious safety concern).
