Nuances of nitrogen nutrition of winter crops

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.

Even with the right grade, an important condition for good harvest is the correct application of fertilizers, taking into account the weather conditions.

The rise in prices for fertilizers forces farmers to accurately consider the amount of each kilogram, because its shortage will have a bad effect on yields. The second point is the complexity of applying granular forms in large areas in specified quantities. The second is the «side of the coin» When using granular forms is a threat of overdose, which carries the risks of deterioration of the phytosanitary condition of the soil, a decrease in plant resistance to frost, lodging crops.
 

 

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.

Ammonium sulfate contains only an ammonium form, approximately in an amount of 20%. Its advantages - lack of mobility, resistance to leaching even with abundant precipitation, minuses - acidification of the soil, the need to protect the soil by liming, alkalinization.

Coal ammonium salts are 17% nitrogen and are a mixture of several ammonium carbonates. This form is able to slow the process of nitrification of fertilizers already in the soil, does not contain toxic compounds in the composition. Once exposed to air (and at a temperature of more than 15 ° C), this compound decomposes into gaseous ammonia (20%), CO2 (50%) and water.

Granular form (GRACSO) of these salts contains 25% nitrogen, convenient for storage - it does not cake. Again, the problem of acidification is expressed, lime protection is needed.

Carbamide (in other words, urea) is a fertilizer known as the most saturated with nitrogen from solid forms. Contains about 46% of the amide nitrogen. This form is interesting because it can enter the plant both through the soil path and through the leaves. Therefore, this is the No. 1 choice for foliar feeding.
Liquid fertilizers - more accurate accounting, but you need special equipment  

 

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.
 

The process of applying fertilizers in the spring should exactly correspond to the weather conditions. On the one hand, the abundance of moisture in the soil improves the result of introducing nitrogen, on the other, one can not be tempted to start work in one of the «February windows». Suddenly falling snow can lead to the washing out of the applied fertilizers and introduce into unnecessary costs.

3 and 4, the stages of vegetation are among the most important - it is at this time that the harvest itself is formed. It was at this time that the main goal of feeding is the strengthening of tillering. Nitrogen deficiency in this period can lead to a shortage of the vegetative mass of plants as a whole and therefore will negatively affect the yield.

The first top feeding should include no more than 30% of the total required dose. Good effect is the introduction of ammonium nitrate, ammonium sulfate, UAN.

The end of the tillering phase and the beginning of the tube outlet are the time for the second fertilizing of the plants. Perhaps soil application, but if the ambient temperature allows, then foliar feeding can be used.

A good solution is the insertion of fertilizer between the plants, which reduces the traumatization of plants and increases the uniformity of distribution, but implementation of this approach is possible with the availability of appropriate equipment.

End of spring is the third time topping up winter wheat. Since the soil, usually at this time dried, then foliar application is one of the best options. The carbamide mixture must contain no more than 4% of the fat.

At this stage, the introduction of nitrogen can reduce the resistance to fungal infection, so it is desirable to share fungicides.

 

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.