Urea is white granular crystals, slightly hygroscopic, can be completely dissolved in water, is a neutral fertilizer. There is no residue left in the soil after urea application, which is called a fertilizer without side effects. However, it has an outstanding feature. The phthalated nitrogen contained cannot be directly absorbed by crops. It must be converted into ammonium nitrogen by the action of microorganisms in the soil before it can be used.
If water is applied immediately after applying urea, it will be dissolved by water. Due to the weak adsorption force between the soil colloid and urea, the flowability of urea in the soil is very large, especially the flooding of large water will make urea drench into the deep layer. Reduce fertilizer efficiency. Therefore, it is not advisable to irrigate immediately after topdressing urea. It is even more unscientific to say that topping fertilizer and applying urea before rain.
At a temperature of 10℃, the conversion time of urea needs 7 to 10 days, 4 to 5 days at 20℃, and two days at 30℃. With this in mind, the irrigation time after top dressing can be determined according to temperature conditions. Second, we must understand the soil conditions. Fertile soils transform faster than barren soils, and clayey soils faster than sandy soils. After applying urea to sticky and fertile soil, it can be irrigated earlier than barren and sandy soil. Thirdly, it must be applied in conjunction with organic fertilizers, because there are many microorganisms in organic fertilizers, which can provide better conditions for urea conversion and speed up the conversion process.
Finally, the method of deep application and covering the soil should be adopted, which can not only avoid the direct volatilization of the exposed, but also increase the chance of contact with the microorganisms in the soil, which is conducive to the adsorption of urea and the product of ammonium carbonate or bicarbonate decomposed and transformed in the soil by the soil colloid. , To provide useful nutrients for crops.
The nitrogen content of urea is between 44% and 46%, and biuret should be ≤0.9% to 1.5%, which is a neutral nitrogen fertilizer. The urea nutrient content is high, suitable for all kinds of soil and a variety of crops, the most suitable for top dressing, especially the effect of extra-root top dressing.
When urea is applied to the soil, it can only be absorbed and utilized by crops after being converted into ammonium bicarbonate. Due to the transformation process, the fertilizer effect is slow, and it is generally applied 4 to 6 days in advance. At the same time, it also requires deep application of soil, and do not irrigate immediately after application to prevent nitrogen from leaching into the deep layer and reduce fertilizer efficiency.
When the urea top dressing, especially the leaf surface, absorbs the nutrients in urea quickly, the utilization rate is also high, and the effect of increasing yield is obvious. When spraying urea, the concentration requirements are stricter. Generally, the concentration of gramineous crops is 1.5% to 2%, fruit trees are about 0.5%, open field vegetables are 0.5% to 1.5%, and greenhouse vegetables are 0.2% to 0.3%. For growing crops, or adult fruit trees, the concentration of urea applied can be appropriately increased.
Disclaimer: Some articles of this website are transferred from the Internet. If the legal rights of third parties are involved, please inform this website for processing. phone
Enzalutimide Intermediates
Cas 179232-29-2 Enzalutamide Intermediate,Enzalutamide Intermediate,Cas 654-70-6 Enzalutamide Intermediates,Cas 143782-23-4 Enzalutamide Intermediates
Shijiazhuang Dingmin pharmaceutical Sciences Co.,Ltd , https://www.dingminpharma.com