Urea is the most concentrated solid nitrogen fertilizer produced in China, and its aqueous solution is neutral. Besides being used as a base fertilizer, it's widely applied as top-dressing for most crops. So, how can we maximize the effectiveness of urea fertilizer? Here are some key practices to consider:
1. **Apply Based on Soil Fertility**
Field experience shows that increasing fertilizer application in medium and low-yield fields can significantly boost crop production. For high-yield fields, maintaining a standard fertilization level is usually sufficient. When using urea as a top-dress, for example, in corn and sorghum, apply 20 kg per mu in high-fertility soil, 23 kg in medium-fertility soil, and 27 kg in low-fertility soil.
2. **Time Top-Dressing During Peak Nutrient Uptake**
The main purpose of top-dressing is to support crop growth during critical stages by supplying essential nutrients. To improve fertilizer efficiency, it’s important to apply urea when crops are in their peak nutrient absorption periods. For corn, this is during the jointing to booting stage; for sorghum, the jointing to heading stage. Rice should be top-dressed during the tillering stage, while sunflowers benefit from application at the budding stage. Wheat and soybeans should receive urea during the three-leaf and early flowering stages, respectively.
3. **Incorporate into the Soil**
Research has shown that when urea is left on the surface for 4–5 days, a significant portion of the nitrogen can volatilize due to ammonification, reducing its effectiveness to about 30%. On calcareous or alkaline soils, losses are even greater. Therefore, it's better to apply urea by digging small pits or deepening furrows to a depth of less than 10 cm, allowing it to mix with moist soil and reduce ammonia loss. When top-dressing rice, keep the water layer shallow—no more than 3–5 cm.
4. **Maintain Distance from Plants**
Urea has a high nitrogen content and strong hygroscopic properties. Applying it too close to the roots or directly into the plant’s heart can cause leaf burn and hinder growth. Always maintain a safe distance from the plants to avoid damage.
5. **Apply Earlier Than Other Nitrogen Fertilizers**
Urea is an organic compound that needs to be converted into ammonium before being absorbed by plant roots. This process requires the action of urease enzymes. As a result, urea should be applied about 7 days earlier than other nitrogen-based fertilizers to ensure optimal availability.
6. **Avoid Mixing with Alkaline Fertilizers**
Since urea is a neutral fertilizer, mixing it with alkaline materials like lime or wood ash can reduce its effectiveness. If mixing is unavoidable, apply them on different days, at least 3–5 days apart. However, combining urea with potassium chloride, phosphate rock, or superphosphate can enhance yield.
7. **Avoid Immediate Irrigation After Application**
Urea must first convert into a form that plants can absorb. Watering immediately after top-dressing can lead to significant losses. In dry fields, avoid flooding and instead use light irrigation. For rice, do not flood the field right after applying urea. Instead, apply small amounts of water every 3–5 days.
8. **Use for Foliar Application**
Urea is highly soluble and causes minimal leaf damage. It diffuses easily through leaves and is efficiently absorbed without causing plasmolysis. It’s ideal for foliar feeding, provided the biuret content does not exceed 2%. The recommended concentration for foliar application varies: 1.5%–2% for most crops, and 1% for broadleaf plants. Apply no more than 0.5–1.5 kg per mu, and spray in the late afternoon when transpiration is low, allowing full absorption overnight.
Auto Parts
This classification mainly includes the aluminum alloy die casting parts using in Auto area,the raw material is aluminum alloy.
In the die casting process,higher specific pressure is required, so that higher filling speed can be obtained.which is beneficial for alloy to overcome mold filling resistance.and effectively fill each part of the cavity.The Casting General Tolerance is Grade GB-CT4.
Process Technology: High pressure die casting, Cold Chamber
Product Dimensions: Customized
Casting General Tolerance: Grade GB-CT4
Flow Processes: Die casting, Degating to remove the residual of the gate, Polishing and Deburring to remove the burrs, Polishing to remove the parting line, flash,CNC Turning, Cleaning, Packaging, Storaging, Shipping
Control Measure: Incoming Material Test, First Article inspection, Routing inspection, Final item inspection, and Outgoing quality control
Inspection Equipment: CMM, Caliper, Plug Gage, Screw Gauge
Application: Machinery Parts
Certificate: IATF16949:2016,ISO14001:2015,ISO45001:2018
Lead Time: 30-35 days
Trade Term: FOB Ningbo
Auto Parts,Automotive Aluminum Parts,Automobile Zinc Parts,Aluminum Auto Parts
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