Among the many scientific branches, there is one whose birth was dictated by the need to combine the knowledge of such natural disciplines as chemistry, botany and agronomy. We are talking about agrochemistry, which studies the nutrition of plants and the use of fertilizers. Calcium nitrate, the properties and the application of which we consider, will help us to get acquainted with the features of agrochemical science.
Everybody wants yummy.
Data from demographic reports indicate that the population of the Earth increases by about 80 million people every year. Nowadays, 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 plant origin. Therefore, the expression "land-nurse" in the best way shows our absolute dependence on high soil fertility.
Twelve percent of the world's population is hungry. This fact forces all branches of the global agro-industrial complex to solve an urgent and vital issue. Namely: how to increase crop production through the use of rational land use methods? The development of the mineral fertilizer industry, which includes calcium nitrate, is one such method. With its help it is absolutely realistic to increase fertility.
10 thousand years ago, since the inception of agriculture, man began to think about the question of how to increase the yield of the plants that feed him. To this end, people began to pay close attention to the soil, deciding to periodically introduce into it organic fertilizer - guano. These are common bird feces. Later, rotted manure of domestic animals was used as an organic fertilizer.
At the end of the 19th century, Russian scientists D. Mendeleev, A. Engelhardt, K. Timiryazev and the German chemist Justus von Liebig proposed the so-called theory of plant mineral nutrition, which became the basis of the science of agrochemistry. Along with organic fertilizers, it was recommended to use mineral salts that contain the most essential elements for plants: nitrogen, phosphorus, potassium. The raw materials for their production were crushed into powder rocks: Chilean nitrate, dolomite, apatite. In the XX century in Russia, England, Germany, the first chemical enterprises were built that produced fertilizer - 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. Compounds belong to the 3rd class: these are moderately hazardous chemicals. With 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 these specific properties, calcium nitrate is still a very useful and necessary compound. To obtain calcium nitrate, nitrous gases and calcium hydroxide are used as promising fertilizers. Calcium nitrate, which is formed as a result of the reaction, is characterized by high purity and can be used as an effective direct fertilizer. That is, it can serve as a direct source of nitrogen readily assimilable to plants. At the same time, calcium nitrate is also an indirect fertilizer. This means that it improves the nutritional properties of the soil itself. In the mineral fertilizer industry, two methods of producing calcite are used:
- Nitric acid affects limestone.
- By production of complex fertilizer. Calcium nitrate in the 2nd way is mined as a by-product.
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, transportability of fruits and seeds. Thus, the apical rot disease affecting plants of the Solanaceae family - tomatoes and peppers, occurs when there is a lack of calcium ions in the soil. Adding to the soil during the growing season granulated or dissolved in water calcium nitrate 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, alkalizing sod-podzolic soils. Calcium nitrate is produced by such major enterprises as Nevinnomyssky Azot in the Stavropol Territory and Azot NAC 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 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.
This property of anions NO is also taken into account.3 – , included in this fertilizer, as the ability to be absorbed by the roots of plants in the spring. That is, nitrogen fertilizer calcium nitrate should be used in the spring. During the sowing period it is introduced directly into the soil. In the summer it is allowed to use a solution of calcium nitrate simultaneously with watering plants.
Measure in everything
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 rules for making calcium nitrate: a maximum of 3 grams per linear meter or 2 kg per hundred square meters. 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 no more than 3 times during the growing season.