Urea is a high concentration of nitrogen fertilizer, is a neutral quick fertilizer, can also be used to produce a variety of compound fertilizer. In the soil does not leave any harmful substances, long-term use without adverse effects. Livestock can be used as feed for ruminants. But in the granulation of the high temperature will produce a small amount of biuret, also known as biuret, inhibit the crop. China provides urea urea urea biuret content should be less than 0.5%. Bioderea content of more than 1%, can not do fertilizer, Urea fertilizer and foliar fertilizer, other application period of urea content should not be too much or too concentrated.
Urea is an organic nitrogen fertilizer, through the soil urease action, hydrolysis into ammonium carbonate or ammonium bicarbonate, can be absorbed by the crop. Therefore, the urea should be applied 4 to 8 days before the crop needs.
Urea is suitable for basal and topdressing, and sometimes for manure. Urea Urea in the transformation before the molecular state, can not be soil adsorption, should be prevented with the loss of water; conversion after the formation of ammonia is also volatile, so urea should be deep casing. (Soil conversion into the soil in a small part of the molecular state dissolved in soil solution, by hydrogen bonding by soil adsorption, most of the other under the action of urease hydrolysis into ammonium carbonate, and then generate hydrogencarbonate and ammonium hydroxide.
NH4 + can then be absorbed by plants and soil colloid adsorption, NCO3 can also be absorbed by plants, so urea does not leave any harmful ingredients after the soil. In addition, Urea the urea-containing biuret can be decomposed into ammonia and carbonic acid under the action of urease. The conversion of urea in the soil is affected by soil pH, temperature and moisture, neutral in the soil, and the soil temperature is appropriate High, the faster the conversion; when the soil temperature of 10 ℃ when the urea is fully converted to ammonium nitrogen need 7 - 10 days, when 20 ℃ to 4 - 5 days, when 30 ℃ to be 2 - 3 days can be. Urea hydrolysis after the formation of ammonium nitrogen, the table will cause the evaporation of ammonia, Urea especially alkaline or alkaline soil is more serious, so the application of urea should be deep soil, paddy fields to deep into the reduction layer. )
Urea is suitable for all crops and all soils and can be used as basal and top dressing. As the conversion of urea in the soil can accumulate a large number of ammonium ions, will lead to 2-3 times the PH unit, coupled with the urea itself contains a certain amount of biuret, its concentration at 500ppm, it will crop roots and Young shoots from the inhibition, so urea should not be used as seed fertilizer.
Urea (nitrogen fertilizer) can promote cell division and growth, so that leaves and leaves lush.
In the hybrid rice seed production technique, in order to increase the outcrossing rate of the parents to increase the amount of hybrid rice seed production or the amount of male sterile lines, the use of red toxin spraying the mother to reduce the degree of parental Of the complete extraction; or spraying parents, adjust the growth of both, so that the flowering time synchronization. As gibberellin prices are more expensive, Urea with its high cost of seed production. People use urea instead of gibberellin in the experiment, in the first stage of the spike, the heading period (20% heading) using 1.5% -2% urea, its breeding effect and gibberellin similar, and will not increase plant height.
True and false identification
A look: true urea is a translucent and uniform size of the colored particles. If the surface color of the particles is too bright or dark, or showing a clear reflection, it may be mixed with impurities, then how long a child, be careful to buy fake urea.
Second check: check the packaging of the production batch and sealing. True urea production bags on the general production batch number clear and positive and negative sides of the edge of the machine sealing; false urea packaging on the production lot number is not clear or no, and most of the use of single-line manual sealing.
Three said: regular manufacturers of urea and the actual weight of the general difference is less than 1%; and fake true urea and standard weight difference is very large.
Four touch: true urea particles size consistent, not easy to agglomerate, Urea and thus feel better; and fake urea hand touch when there is burning sensation and stabbing feel.
Five burns: pure urea on the red charcoal quickly melt, take white smoke, there are ammonia flavor. Such as charcoal on the fierce combustion, hair light, and with "Chi Chi sound"; or melting not, then which will be mixed with impurities.
Six smell: regular manufacturers of urea under normal circumstances without volatile odor, but in the damp or by the high temperature to produce ammonia; if the normal case of strong volatile, the urea contains impurities.
China's urea production capacity is undoubtedly, in addition to domestic demand, the off-season does need to export to ease the pressure on sales. But Tang Feifei said that regardless of the amount of exports, urea still have to face domestic demand, domestic demand is the fundamental manufacturers, Urea coupled with the abolition of various preferential policies, urea commodity characteristics are more and more obvious.
Just now, in the basic situation of the same farmland, in recent years, agriculture has just been slow to grow, coupled with the farmers used fertilizer fixed, fertilizer has been long-term fixed; at the same time the new generation of farmers to feed their families, migrant workers, part of the farm Abandoned, abandoned the phenomenon, although no authoritative statistics, but the most intuitive performance is the slow decline in fertilizer.
Field crops on the demand for urea, as always, coupled with the people (603883, stock it) for many years with fat habits base fertilizer, mention the seed will still choose urea, and summer fertilizer is more flexible, high nitrogen compound fertilizer, peptide release and so on Can meet the crop growth needs; peptide urea because of its profit margins greater than ordinary urea, in the dealer's promotion, virtually squeeze some of the amount of ordinary urea.