There is one among the many scientific branches, one whose birth was dictated by the need to combine the knowledge of such natural disciplines as chemistry, botany and agronomy. It is about agrochemistry, which studies the nutrition of plants and the use of fertilizers. Calcium nitrate, whose properties and applications we will consider, will help us become acquainted with the peculiarities of agrochemical science.
Everyone wants a delicious.
Data from demographic reports indicate that the population of the Earth increases by about 80 million people annually. Today more than 7 billion people live on the planet. They all need food. The main products that are included in the diet of the vast majority of people are those that are of vegetable origin. Therefore, the expression "land-breadwinner" best shows our absolute dependence on high soil fertility.
Twelve percent of the world's population is starving. This fact forces all branches of the world agro-industrial complex to solve an urgent and vital issue. Namely: how to increase the production of crop production by applying rational methods of land use? The development of the mineral fertilizer industry, which includes calcium nitrate, is one such method. With its help, it is absolutely real to increase fertility.
Ten thousand years ago, from the moment of the birth of agriculture, a man began to think about the question of how to increase the yield of plants that feed him. For this, people began to pay close attention to the soil, deciding to periodically add organic fertilizer to it - guano. These are the usual feces of birds. Later, as organic fertilizer began to use the overgrazed manure of domestic animals.
At the end of the nineteenth century, Russian scientists D. Mendeleyev, A. Engelhardt, K. Timiryazev and German chemist Justus von Liebig proposed the so-called theory of mineral nutrition of plants, which became the basis of the science of agrochemistry. Along with organic fertilizers, it was recommended to use mineral salts containing the most essential elements for plants: nitrogen, phosphorus, potassium. Raw materials for their production were powdered rock: Chilean nitrate, dolomite, apatite. In the 20th century, the first chemical enterprises were built in Russia, Britain and Germany, producing tuks - mineral fertilizers on an industrial scale.
Calcium nitrate is a white crystalline substance, very hygroscopic and perfectly soluble in water. It has several more names: calcite, calcium nitrate, calcium nitrate. The compounds belong to Class 3: they are moderately hazardous chemicals. During shocks and shocks, the substance ignites with an explosion, therefore emulsion industrial mixtures containing a solution of calcium nitrate are used in open mineral deposits for blasting operations.
The substance is toxic: in contact with the mucous membrane of the eyes or epidermis of the skin, it causes thermal damage. Using calcium nitrate as a fertilizer, it is necessary to take precautions, as in chemical laboratories, this substance is stored separately from other reagents.
One of the best
Despite such specific properties, calcium nitrate is still a very useful and necessary compound. To obtain calcium nitrate, nitric gases and calcium hydroxide are used as a promising fertilizer. Calcium nitrate, formed as a result of the reaction, is characterized by a special purity and can be used as an effective direct fertilizer. That is, it can serve as a direct source of nitrogen easily assimilable to plants. At the same time, calcium nitrate is an indirect fertilizer. This means that it improves the nutritional properties of the soil itself. In the mineral fertilizer industry, two methods are used to produce calcite:
- Nitric acid is affected by limestone.
- In the production of complex fertilizer. Calcium nitrate is produced as a by-product in a 2-nd way.
Calcium nitrate is successfully used not only as a source of rapidly assimilable NO3 (-) ions that saturate the soil with nitrogen, but also as a means of influencing the characteristics of the plants themselves: their resistance to diseases, pests, keeping quality and the transportability of fruits and seeds. Thus, the disease of vertex rot, affecting the plants of the family of nightshade - tomatoes and peppers, arises with a lack of calcium ions in the soil. The introduction into the soil during the growing season of granulated or dissolved in water calcium saltpeter prevents mass loss of the crop.
Calcite is considered one of the best among nitrate fertilizers also because, unlike amide fertilizers (nitrate and ammonium chloride), it does not acidify the soil. Therefore, calcium nitrate, calcium carbonate and its hydroxide are used as fertilizers that alkalize sod-podzolic soils. Calcium nitrate is produced by such large enterprises as Nevinnomyssky Azot in the Stavropol Territory and NJSC Azot in the Tula Region, and abroad it is produced in large quantities in Japan, Germany and Norway (for example, the world's largest supplier of mineral fertilizers Yara).
At the right time and in the right place
The feasibility of using nitrogen fertilizer as calcium nitrate, depends on the type of soil and time of year. The best soils are considered sod-podzol, containing excess hydrogen ions and therefore called sour. Due to the alkaline properties of Ca(NO3 )2. it neutralizes the acidity of the soil, thereby improving its agrochemical characteristics.
Also taken into account is the property of anions NO3 – , included in the composition of this fertilizer, as the ability to be absorbed by plant roots in the spring. That is, nitrogen fertilizer calcium nitrate should be used in the spring. In the sowing period, it is introduced directly into the soil. In summer it is allowed to use a solution of calcium nitrate simultaneously with watering the plants.
Measure in all
Modern man must advantage of this advice of the Delphic Oracle, including the issue of the application of mineral, especially nitrogenous, fertilizers, among them calcium nitrate. It has been experimentally proven that an excess in the soil due to violations of inclusion often leads to the accumulation in the topsoil of the earth salts of nitric acid. Its abundance in harvested crops can be harmful to human health. Like a time bomb, nitrates, and especially nitrites, gradually destroy the gastrointestinal tract and the immune system.
That is why it is necessary to strictly observe the norms of applying calcium nitrate: a maximum of 3 grams per running meter or 2 kg per hundred parts. If a solution of calcium nitrate is used, its application rate is 800-900 l / ha. The concentration of the substance should not exceed 1-2%. Top dressing is carried out not more than 3 times during the vegetation period.