The potassium nitrate is a chemical compound that acts as an oxidizing agent and which has as its empirical formula the formula KNO3. It is the potassium salt of nitric acid and is obtained in the laboratory through two main methods: either by reacting nitric acid with potassium carbonate or by allowing an ionic exchange between sodium nitrate and potassium chloride. In both cases, what can be obtained is a solid and colorless salt, with a slightly bitter taste.
The most common name by which it is identified in trade (and which has identified it since ancient times) is “Nitro” or “Salnitro”. It lends itself well to numerous uses both on an industrial and agricultural level and is widely used as a propellant, even at a hobby level.
Potassium nitrate: history
Potassium nitrate was known since ancient Roman times, from which it was nicknamed ” natrum “. It was used as a detergent for fine tableware and jewelry and allowed the discovery of glass.
According to the writings, it seems at the time of Pliny, during a trip to the sea the crew used nitro loaves to place the pots used to cook the dishes. It seems that the nitro, due to the heat of the flame and mix with the sand of the sea, gave rise to small shining fragments and a crystalline and indecipherable liquid, which today we know for sure to be the ancestor of the current common glass. Ancient populations exploited the nitro present in the natural reserves of India and South America, but once its importance was discovered (also and above all as a component of gunpowder, in times of war) its artificial production spread in the laboratory.
Potassium nitrate: miraculous fertilizer for fertigation
During the twentieth century, potassium nitrate assumed enormous agricultural importance and its use as fertilizer has become increasingly common. It is considered to be a real miraculous fertilizer, but it also has its many defects, which we will discuss better shortly.
Starting from the merits, we can say with certainty that potassium nitrate is widely used because it is soluble in water. This peculiarity makes it perfect to be used with modern fertigation techniques, a very common and extremely convenient practice from both efficiency and the reduction of the use of expensive labor. Potassium nitrate is used extremely frequently because it manages to provide plants with two of the fundamental elements for their growth: potassium and nitrogen. Two very important and often deficient molecules in some soils or due to particular climatic conditions. Nitro is all the more soluble and qualitatively valid the higher its degree of purity.
Costs can, therefore, be extremely variable and change, precisely, about the purity of the same. If used by means of fertigation systems, the potassium molecules are not able to penetrate deeply into the soil and for greater and better diffusion it is necessary to act at a later time through manual transplants in the soil itself or through direct leaves, to be associated automatic irrigation.
A limit which, however, does not involve a great deal of time or money. It is used in the standard quantities of 1g / l of liquid solution. Very little is enough. In agriculture, it is used to optimize nutrition in stressed and/or blocked crops, both because of metabolic stress and because of extreme situations, such as extremely frigid climates or calcareous soils that are unsuitable for their development.
Potassium nitrate: what is it for?
Potassium nitrate is among the most expensive fertilizers, especially if of good quality. However, it is probably one of the richest and most balanced in terms of nutrients and very little is needed to achieve the desired results. Its extreme solubility makes it easy to use both on an industrial and amateur level and its use is quite safe, provided that the doses indicated on the packaging or defined by the standards are respected.
An excess of potassium salts can certainly lead to loss of crops.
It is very suitable for accentuating the coloring of fruits and vegetables. Even if you do not know the composition of the land, which hour you would like to regulate “by eye”, it should be used in the following cases :
- Tomato crops with uneven ripeness and poor consistency;
- Small, low-quality fruits;
- Cereal crops with weak stems, small grains, and poor yield both in terms of weight and quantity.
Potassium nitrate as a food additive
One of the many possible uses of potassium nitrate is food. It is one of the most used preservatives in the food industry and it is also one of the most harmful. If, in fact, its use as fertilizer does not involve particular health risks, its direct intake would seem to be one of the major causes of the spread of tumors of the stomach and esophagus. This is because nitrites and nitrates (the name of the potassium nitrate used at the food level is E252) once in contact with the heat deriving from the processing of the meat – in fact, they are mainly used as preservatives for meat and sausages – they can undergo chemical alterations that allow the release of potential carcinogens, which should never be abused.
Agricultural use is instead free from these problems, also because the actual amount of nitrate absorbed by the organism with the consumption of the products grown with it is absolutely negligible. The potassium nitrate is already dissolved in plenty of water during irrigation and the absorption is very minimal and it is very concentrated in the external peel, which is sufficient to wash well before consumption (remember that nitrate is salt and, as such, tends to recrystallize once the water has evaporated).