What is nitrogen fertilizer? What are the common nitrogen fertilizers? Identification methods of nitrogen Fertilizer

What is nitrogen fertilizer? Nitrogen fertilizer is a kind of fertilizer, which is the main fertilizer to promote the growth of roots, stems and leaves of flowers. Nitrogen in it plays a very important role in crop growth. The application of nitrogen fertilizer can not only increase the yield of agricultural products, but also improve the quality of agricultural products. What are the common nitrogen fertilizers? What are the identification methods of nitrogen fertilizer? Let's take a look at it.

What is nitrogen fertilizer?

Nitrogen fertilizer is a chemical fertilizer containing crop nutrient element nitrogen. Elemental nitrogen plays a very important role in crop growth. It is a component of amino acids in plants, a component of proteins, and a component of chlorophyll, which plays a decisive role in plant photosynthesis. Nitrogen can also help crop differentiation, the application of nitrogen fertilizer can not only increase the yield of agricultural products, but also improve the quality of agricultural products. Nitrogen fertilizer is also a kind of inorganic salt.

Common brands of nitrogen fertilizer

Sinochem Sinochem

Suitable for chemical

Kim Jong-il Kingenta

Stanley STANLEY

Yangfeng YF

Yuntianhua

Luxi LUXI

Wengfu WF

Takeda

Cashley.

The role of nitrogen fertilizer

Nitrogen fertilizer is a chemical fertilizer containing crop nutrient element nitrogen. The main functions of nitrogen fertilizer are to increase the total biological amount and economic yield, to improve the nutritional value of agricultural products, especially to increase the protein content in seeds and improve the nutritional value of food.

Nitrogen is the main component of protein in crops. Without nitrogen, nitrogen white matter cannot be formed. Without protein, there can be all kinds of life phenomena. In crops, parts that contain more protein (such as seeds) also contain more nitrogen, and parts that contain less protein (such as senescent stems) also contain less nitrogen. Not only that, nitrogen is also a component of chlorophyll and many enzymes. Chlorophyll is a necessary substance for crop photosynthesis, and enzyme is the catalyst for the transformation of various substances in crops. Nucleoproteins and plant alkaloids also contain nitrogen. Thus it can be seen that nitrogen plays an extremely important role in crop nutrition. Crops begin to absorb nitrogen from the appearance of the first true leaf.

When the nitrogen fertilizer was insufficient, the crops generally showed that the plants were short and weak, the leaves were yellow-green, yellow-orange and other abnormal green, the basal leaves gradually dried and withered, the root branches were few, and the tillers of cereal crops decreased significantly, even without tillering. poor panicle differentiation, few branches, small spike shape, significant premature senescence and early maturity, and reduced yield.

When excessive nitrogen fertilizer is applied, crops are generally shown as follows: excessive growth, continuous birth of axillary buds, too many tillers, hindering the normal development of reproductive organs, so as to delay maturity, leaves are dark green, stems and leaves are tender and succulent, the content of soluble non-protein nitrogen in the body is too high, easy to be damaged by diseases and insect pests, lodging easily, cereal crops are not full (low 1000-grain weight), blighted grains are many, and crop yield is reduced.

Urea is the main nitrogen fertilizer commonly used now. Urea is an organic nitrogen fertilizer, which is hydrolyzed into ammonium carbonate or ammonium bicarbonate by urease reaction in soil before it can be absorbed and utilized by crops. therefore, urea should be applied 4-8 days before the fertilizer period of crops. At the same time, the final product of urea decomposition in the soil is ammonium carbonate, which is very unstable and decomposes into free ammonia in the soil or on the soil surface, which is easy to volatilize. Like other nitrogen fertilizers, urea should be applied in the morning or evening, preferably after rain or cloudy days, and at noon on sunny days. Urea is a unit fertilizer, which should be used in conjunction with phosphate fertilizer or other chemical fertilizers, so that it can not only meet the needs of crops for various nutrients, but also play an auxiliary role between fertilizers.

Development of nitrogen fertilizer

Since the 20th century, the production of nitrogen fertilizer has been playing an important role. This is mainly because the average nitrogen fertility of the world soil is not high, nitrogen is not easy to accumulate in the soil, and modern intensive agriculture promotes the excessive loss of soil organic matter and nitrogen, and the yield increase of unit nitrogen is higher than that of phosphorus and potassium under most conditions.

The development of nitrogenous fertilizer industry in China was relatively late, and two nitrogenous fertilizer plants were built in Dalian and Nanjing in 1935 to produce ammonium sulfate. Before 1949, the cumulative amount of nitrogen fertilizer produced in China was 600000 tons (N), which was mainly used in coastal provinces. After the founding of New China, the nitrogen fertilizer industry developed rapidly before phosphorus and potassium fertilizer. In 1953, the annual output of nitrogen fertilizer in China was 50, 000 tons in terms of nutrients, exceeding the highest annual output of 48000 tons in 1941. After the first and second five-year plans for national economic development, by 1965, the national nitrogen fertilizer output had reached 1.037 million tons (N), an increase of nearly 10 times over 1953. Since then, after a 10-year period of great development of large, medium and small chemical fertilizer plants from 1969 to 1978, more than 1000 small nitrogenous fertilizer plants and more than 10 large nitrogenous fertilizer plants with an annual output of 300000 tons of synthetic ammonia have been built throughout the country. By 1983, the national nitrogen fertilizer output had soared to 11.094 million tons (N), making it the second largest nitrogen fertilizer producer in the world after the former Soviet Union. In 1991, China's nitrogen fertilizer output reached 15.1 million tons, ranking first in the world.

What are the common nitrogen fertilizers

Ammonium nitrogen fertilizer

Ammonium nitrogen fertilizer includes ammonium bicarbonate (NH4HCO3), ammonium sulfate {(NH4) 2SO4}, ammonium chloride (NH4Cl), ammonia (NH3.H2O), liquid ammonia (NH3) and so on.

Common characteristics of ammonium nitrogen fertilizer:

The main results are as follows: 1. Ammonium nitrogen fertilizer is easily absorbed by soil colloids and partially enters the crystal layer of clay minerals.

2. Ammonium nitrogen is easy to oxidize to nitrate.

3. Ammonia is easy to lose in alkaline environment.

4. High concentration of ammonium nitrogen is easy to be toxic to crops.

5. Excessive ammonium nitrogen absorbed by crops can inhibit the absorption of calcium, magnesium and potassium to a certain extent.

Nitrate nitrogen fertilizer

Nitrate nitrogen fertilizer includes sodium nitrate (NaNO3), calcium nitrate {Ca (NO3) 2}, ammonium nitrate (NH4NO3) and so on.

Common characteristics of nitrate nitrogen:

The main results are as follows: 1. it is soluble in water and moves quickly in the soil.

2. NO3- is mainly absorbed, and nitrate is easily absorbed by crops.

3. Nitrate fertilizer had no inhibitory effect on crop absorption of calcium, magnesium, potassium and other nutrients.

4. Nitrate is an anion with negative charge, which can not be absorbed by soil colloid.

5. Nitrate is easily reduced to gaseous state (NO, N2O, N2) by denitrification and escapes from the soil.

Amido nitrogen fertilizer

Urea: molecular formula CO (NH2) 2, nitrogen content 44Mel 46%. Solid fertilizer, the high quality fertilizer with the highest nitrogen content, is a chemically synthesized organic small molecular compound. It is soluble in water, and the aqueous solution is neutral; it is easy to dissolve in high temperature and humidity. A small part of physiological neutral fertilizer was absorbed in molecular state after being applied to soil, and most of it was converted into (NH4) 2CO3 by urease. The fertilizer effect was slower than that of NH4+-N and NO3--N. When it was used as topdressing, it should be applied 5 days in advance, and there was no adverse reaction to soil. Can be used as base fertilizer, topdressing, not recommended as seed fertilizer, the most suitable for extra-root topdressing; suitable for all kinds of soil and crops, calcareous and alkaline soil application should be deep cover soil to prevent ammonia volatilization.

Long-acting nitrogen fertilizer

Also known as slow-release or slow-release nitrogen fertilizer, controlled nitrogen fertilizer, difficult to dissolve in water or difficult to be decomposed by microorganisms, slowly release nutrients in the soil.

Common characteristics of long-term nitrogen fertilizer:

1. Low solubility, slow release of nutrients, reduction of nitrogen leaching, volatilization, fixation and denitrification.

2. The fertilizer effect is stable and long, which can meet the supply of nitrogen in the whole growth period of crops.

3. It can be used in large quantities at one time, saving labor and effort.

Simple identification of nitrogen fertilizer

The most counterfeit nitrogen fertilizers on the market, such as fake urea, generally have two situations: one is that the composition of the whole bag is inconsistent. If the fluidity at the upper mouth of the bag is good, the lower one does not flow or even agglomerate, and a strong smell of volatile ammonia can be smelled. Basically, it can be judged that the top is urea and the bottom is pseudo-mixed ammonium carbonate. If the upper and lower fluidity is very good, but the color and particle size of the particles are different, it may be pseudo-mixed ammonium nitrate; another case is that the composition of the whole bag of fertilizer is the same, and the common counterfeits are: granular ammonium nitrate and so on. There are also some macromolecular organic compounds, such as polyols. Although the particles, color and solubility of the above substances are very similar to urea, they can still be identified by the following methods.

Appearance

Urea is a white translucent particle with no reflection on the surface, while ammonium nitrate has obvious color and reflection on the surface; polyol is an opaque milky white particle with no color and no reflection.

Hand feeling

Urea is smooth, loose and has no sense of moisture; ammonium nitrate is smooth but d polyols are loose but not very smooth.

Baked Wheat Cake

When the three substances are put on the red charcoal or iron plate, urea melts, gives off white smoke and smells of ammonia; ammonium nitrate burns violently, emits strong light and white smoke, and is mixed with a "snort" sound; polyols decompose and burn, but there is no smell of ammonia.