Potassium nitrate (potassium nitrate)

This fertilizer has another name – Indian saltpeter (1). This is explained by the fact that it is in India that one of the largest deposits is located, where the mineral form of potassium nitrate, nitrocalite, is mined.

As you know, potassium nitrate is used not only in agriculture. In the Middle Ages, it was used to make gunpowder. Potassium nitrate itself was obtained in a very curious way – from heaps of manure mixed with limestone and covered with turf. 

Nowadays, potassium nitrate is obtained thanks to the deposits of nitrocalite. The largest are located in India, Bolivia, Australia, South Africa, Chile, USA, Sri Lanka and in our country.

What is potassium nitrate

Potassium nitrate (KNO₃) is an effective water-soluble fertilizer with a high content of potassium and nitrogen. 

Outwardly, it looks like translucent crystals without a pronounced odor. It is used as a potassium-nitrogen fertilizer. For summer cottages, the plot is available in packs of 20 and 500 g.

The composition of potassium nitrate

Potassium nitrate contains up to 45 – 46% potassium and 13% nitrogen (2).

Properties of potassium nitrate

In this fertilizer, nitrogen is responsible for activating the growth of green mass, and potassium is responsible for the development of the root system and improving the quality of fruits. In general, potassium nitrate activates the metabolic processes of plants, strengthens the immune system, regulates growth and ensures the full ripening of fruits and their taste.

It is recommended for fertilizing fruit and berry crops, especially apple, pear, currant, raspberry and strawberry, as well as vegetable plants – cucumbers, tomatoes, eggplants, peppers and beets. 

It is undesirable to use potassium nitrate when growing green crops, potatoes and radishes. In small doses, you need to make under various types of cabbage. 

The use of potassium nitrate in the garden with step by step instructions

Potassium nitrate is used for growing both in open ground and in greenhouses, for indoor flowers.

Most effective for feeding crops that do not tolerate chlorine.

making Dates

In central Our Country, the optimal time for the introduction of potassium nitrate is the beginning of budding, flowering and fruit set, i.e. in most cases – May-June. Starting from August, potassium nitrate is not fed. 

It is not recommended to allow the sun to hit the leaves of plants after foliar feeding with potassium nitrate.

Dosage of application

When using potassium nitrate, application rates must be observed. First you need to know the level of soil acidity, because on light acidic soils this saltpeter can be harmful. And in general, on acidic soils, it should be used to a limited extent and in no case should the application rate be exceeded.

For top dressing use the following doses: 

• for fruit trees – 25 g (5 teaspoons) per 10 liters of water;
• for shrubs and seedlings of the 2nd year of planting – 20 g (4 teaspoons) per 10 liters of water;
• for ornamental plants – 15 g (1 tablespoon) per 10 liters of water;
• for vegetable crops – 25 g (5 teaspoons) per 10 liters of water;
• for foliar top dressing – 8 g (1,5 teaspoons) per 10 liters of water. 

To prepare the solution, you need to take warm water – 18 – 22 ° C.

Application methods

This fertilizer is applied in liquid form to the soil or used for foliar feeding of plants. 

When feeding trees and shrubs at the root, it is recommended to pour the solution into the irrigation grooves at the rate of 8 liters per 1 sq. m. 

When feeding flowers and vegetable crops – in the root zone at the rate of 4 liters per 1 sq. m beds or flower beds. 

When foliar feeding, it is important to completely wet the leaves.

Popular questions and answers

We asked about potassium nitrate agronomist Oleg Ispolatov – he answered the most popular questions of summer residents.

Sources of

1. Spencer, Dan. Saltpeter: The Mother of Gunpowder // Oxford, UK: Oxford University Press, 2013 – 256 с.
2. Shuvaev Yu.N. Soil nutrition of vegetable plants // M.: Eksmo, 2008 – 224 p.