The most important direction in plant growing is the development and introduction into operation of plant varieties with the highest possible productivity. Another direction for the application of efforts is the creation of new ones, the improvement of existing technologies for the introduction of mineral fertilizers, plant protection products. Of course, the improvement of the fertilizers themselves is also desirable, but today it is not very possible. Half of all world agrocenoses are grains, among them winter crops prevail. In countries with developed agriculture, wheat is the basis of the diet of the majority of the population. Wheat can produce high yields in a wide range of latitudes and climatic regions.
If we compare the productivity of Ukraine with other countries, then we can mention Argentina, Great Britain and Australia. However, these countries are showing better results due to the fact that they have better control of the application of fertilizers, their accounting. The average figure per hectare in Ukraine is about 26-35 centners. At the same time in the UK, these figures are already almost 78 centners. The fact that Ukraine has significant land resources means little in the current conditions of intensive land use and the acute need to properly use fertilizers. Without the latter, any soil quickly degrades and ceases to give the expected return in the form of a crop. Theoretically, 50-60 million tons of cereals can be annually received from the lands of Ukraine.
Today, nitrogen fertilizers are represented by two main groups: solid and liquid. According to the form of nitrogen in them, they are divided into:
Ammonium nitrate - «old-timer» in the fertilizer market. Contains at once two forms of nitrogen (nitrate and ammonium). The soil-absorbing complex easily and quickly absorbs this fertilizer. The first include NH4 + cations, followed by the NO3- anions. As a consequence, when working on sod-podzolic soils, there is a need to protect the soil from acidification. Black soils are rich in their own bases, so they easily resist acidification. A good solution in this case is lime-ammonium nitrate. It contains about 20% nitrogen, and calcium carbonate protects the soil from acidification
Calcium nitrate perfectly solves the problem of acidification of the soil, it is hygroscopic and therefore quickly turns into a hydrated form.
Of the liquid fertilizers should be listed anhydrous ammonia, UAN, ammonia water. Due to the smaller number of technological operations (there is no need to evaporate, granulate) the cost is lower, the price too. However, the requirements for storage, transportation and application technology are changing.
Of all liquid fertilizers, anhydrous ammonia is the most concentrated (up to 82% nitrogen). The boiling point is 34°C. C. When applied to the soil, it is converted into ammonium hydroxide in contact with soil moisture. It is better absorbed by soils that are rich in organic.
Ammonium water contains about 21% nitrogen. Such water should be introduced to a depth of at least 10 cm. If the soils of light mechanical composition are present on the entire depth of the plow layer. It binds well to the soil, does not wash out. The positive property of this fertilizer is soil sterilization, destruction (partial) of fungi, and mouse rodents in winter wheat.
The above-described forms have the disadvantage that they contain only one form of nitrogen. UAN is a mixture of all three forms: carbamide, ammonium, amide. It contains 35.4% of carbamide, 44.3% of saltpeter, water of 19.4% and 0.5% of ammonia water. Free ammonia is absent, so it does not escape into the atmosphere. But it is very desirable to seal when applying to avoid losses already from the top layer of the soil at high ambient temperature and dry soil.
This form provides the maximally prolonged effect, since nitrifying bacteria transfer the ammonium form to nitrate, before this the amide goes into ammonium form. UAN is very suitable for use in autumn for soil cultivation or during the growing of winter wheat varieties, for foliar top feeding.
Autumn fertilization should take into account the risk of overgrowing of plants. Therefore, up to 30 kg/ha of nitrogen is applied to a depth of up to 15 cm. Otherwise, growing of plants and their death from freezing in winter can be obtained. In the spring, the nitrogen introduced in time stimulates the rapid growth and renews vegetation of plants.
Some large enterprises make a risky approach to introducing anhydrous ammonia in the autumn, at a rate of up to 150 kg/ha of nitrogen. This simplifies the care of plants in the spring, but in case of unstable weather conditions, it is fraught with loss of part of the crop.
Not necessarily a source of nitrogen should be fertilizer. Remains of previously grown plants, siderates can also give winter wheat nitrogen. The decline in animal husbandry led to a significant increase in the price of manure, however, many people can afford to grow syderates. Bean plants are the leaders in this list (peas, soybeans). It is possible to use mustard or even rape for this purpose. The decomposition of such fertilizer in the soil enriches it with fly ash, contributes to the preservation of a significant amount of moisture in the soil.
Correctly selected components, their order of introduction increase the yield of any crop, the quality of its grain.