It is a kind of nitrogenous fertilizer with high nitrogen content, which belongs to neutral and quick acting fertilizer. Urea, as the end-product of protein catabolism in some mammals and fish, is used as nitrogenous fertilizer for corps.
It is easy to preserve and use. Therefore, it has been widely used nitrogenous fertilizer in agricultural production. Global Urea Production in Asian areas produce most of urea fertilizer. It reached Urea capacities are high in Africa, Europe and North America. China is a big country of urea fertilizer in production and consumption, followed by India. Application of Urea Urea is a kind of vitally important fertilizer in agriculture production.
Because of the highest nitrogen content and long-lasting effect, urea is in widespread use for corps. The main functions of urea are as followings. Using in flowering phrase: When plants are in nitrogen deficiency, the flowers are small. Apply urea fertilizer to plants can improve the condition. Using in fruit stage: It is the critical period for plants in fruiting.
Colour and lustre, fruit size and fruit setting rate have direct influence on economic benefit. At the same time, plants is easy to lack of nitrogen. As nitrogen supplier, urea is dispensable in this period. Using in iron fertilizer: The production of iron fertilizer is increasing. Losses might be quite low in the spring if the soil temperature is cold.
Also, half of 28 percent liquid N is urea. The same thing happens with this half as with regular urea. Tables 1 and 2 show that, after a few days, warm temperatures or high pH would cause losses.
Table shows percent of surface-added urea volatilized as ammonia at different temperatures and days on the surface. Urea was added on a silt loam soil at pounds of N. Table shows the percent of surface-added urea volatilized as ammonia at various soil pH levels and days on the surface. Urea was added on silt loam soil at pounds of N per acre. Urea can readily be nitrified — that is, converted to nitrate NO3 — even when applied in late fall, and can be quite susceptible to denitrification or leaching the following spring.
A two-year study conducted in Waseca compared late-October applications of both AA and urea for continuous corn Table 3. Data show a 6-bushels-per-acre advantage for AA over urea when applied in the fall without a nitrification inhibitor. But when N-Serve was added, AA showed a bushels-per-acre advantage.
Table shows corn yields as influenced by N source, time of application and nitrification inhibitor in Waseca. Yield figures are an average of to , after applying pounds of N per acre. Studies that continuously use urea have been conducted in Lamberton since Corn yields over a year period averaged 5 to 6 bushels per acre higher with spring application of urea compared to the fall plowed-down application Table 4.
This is especially true in south-central Minnesota and Iowa. But when soil-moisture content is high, fall applications of urea haven't performed as well as AA. If properly applied, urea and fertilizers containing urea are excellent sources of nitrogen for crop production.
Soil moisture determines how rapidly this conversion takes place. When an urea particle dissolves, the area around it becomes a zone of high pH and ammonia concentration. This zone can be quite toxic for a few hours. The free ammonia that has formed can kill the seed and seedling roots within this zone. Fortunately, this toxic zone becomes neutralized in most soils as the ammonia converts to ammonium.
Usually it's just a few days before plants can effectively use the nitrogen. Although urea imparts an alkaline reaction when first applied to the soil, the net effect is to produce an acid reaction. Urea or materials containing urea should, in general, be broadcast and immediately incorporated into the soil. If applying urea-based fertilizer in a band, separate it from the seed by at least 2 inches of soil.
Under no circumstances should urea or urea-based fertilizer be seed-placed with corn. With small grains, you can generally apply 10 pounds of nitrogen as urea with the grain drill at seeding time, even under dry conditions. Under good moisture conditions, you can apply 20 pounds of nitrogen as urea with the grain drill.
Research from North Dakota State University indicates that, under dry conditions, urea can reduce wheat stands more than 50 percent Table 5.
This was for urea applied with a grain drill in a 6-inch spacing, at the rate of more than 20 pounds of nitrogen per acre. University of Wisconsin research indicates that seed-placed urea with corn, even at low rates of nitrogen, is very toxic to the seed and greatly reduces yields Table 6. However, when urea was side-placed as a 2-byinch starter, researchers noted little, if any, damage Table 7. In Minnesota, good crop production usually requires an application of more than 20 pounds of nitrogen per acre.
Farmers can avoid damage from urea by broadcasting most of the urea nitrogen fertilizer ahead of seeding. Data in Table 8 indicate that urea broadcast prior to seeding is equal to or more effective than similar ammonium nitrate treatments.
Urea can be bulk-spread, either alone or blended with most other fertilizers. This lack of weight produces a shorter distance-of-throw when applying the fertilizer with spinner-type equipment. In extreme cases, this will result in uneven crop growth and wavy or streaky fields. Urea and fertilizers containing urea can be blended quite readily with monoammonium phosphate or diammonium phosphate The main function of Urea fertilizer is to provide the plants with nitrogen to promote green leafy growth and make the plants look lush.
Urea also aids the photosynthesis process of plants. However, Urea must not be mixed with any superphosphate unless applied immediately after blending as Urea reacts with superphosphate liberating water molecules.
This will produce a damp material that is hard to store and apply. Click here to Download.
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