Potassium Nitrate (13:0:45)
Soluble, chloride-free potassium with nitrate nitrogen — the fruiting-stage grade for fertigation and foliar sprays on fruit and vegetables.
- Composition
- 13% N (nitrate), 45% K₂O, no chloride
- Form
- Fully water-soluble
- Price
- Premium (non-subsidised)
- Best for
- Fruiting stage — fertigation & foliar
Overview
Potassium nitrate carries about 13% nitrogen (all as immediately available nitrate) and 45% potassium (K₂O), and no chloride. It is fully water-soluble, so it is made for drip fertigation and foliar sprays rather than broadcasting — an expensive way to buy potassium on a field, but exactly the right tool for spoon-feeding a high-value crop.
Its moment is the fruiting and ripening stage, when a crop’s potassium demand peaks: it supports fruit size, colour, sugar and shelf life, and the nitrate nitrogen is taken up cleanly without pushing soft, late vegetative growth. Grapes, pomegranate, tomato, chilli and banana under drip are its natural home.
What it is and when to reach for it
- A soluble, chloride-free potassium source with nitrate nitrogen — reach for it at the fruiting and ripening stage of fruit and vegetables.
- It is a fertigation and foliar grade, not a field basal; on a field, MOP or SOP are far cheaper per kg of potassium.
- It shines under drip on grapes, pomegranate, tomato, chilli and banana.
How to apply it well
- Fertigation: apply in small, frequent doses through the fruiting stage per the crop’s schedule, flushing lines afterwards.
- Foliar: spray at roughly 0.5–1% in the cool of the morning or evening to support fruit set and fill.
- Because it is chloride-free, it is safe on the chloride-sensitive fruit crops where MOP would risk quality.
Common mistakes
- Broadcasting it on a field as a basal — a very expensive way to buy potassium.
- Using it as the crop’s only potassium source from sowing, instead of building a base with cheaper MOP/SOP and topping up at fruiting.
- Spraying in strong midday sun, which scorches leaves and wastes the spray.
Crops it is used on
Open a crop for its full nutrient schedule.
Common questions
What is potassium nitrate used for?
It is a water-soluble, chloride-free source of potassium and nitrate nitrogen, used mainly in drip fertigation and foliar sprays at the fruiting and ripening stage of high-value fruit and vegetables — grapes, pomegranate, tomato, chilli, banana — to support fruit size, colour, sugar and shelf life.
Can I use potassium nitrate as a basal fertiliser?
You can, but it is not economical — on a field, MOP or SOP deliver potassium for a fraction of the price. Potassium nitrate is best kept for fertigation and foliar feeding at the fruiting stage, on top of a cheaper potassium base.
How much potassium nitrate for a foliar spray?
A common foliar concentration is about 0.5–1% (roughly 5–10 grams per litre of water), sprayed in the cool morning or evening at the flowering-to-fruiting stage. Do a small jar test before tank-mixing with anything else.
Composition and doses follow ICAR / Soil Health Card guidance; prices are the notified subsidised rates for the season shown and are guidance, not a quote. A soil test for your field always beats a general rate. See our editorial policy.