Crop top dressing fertilizer has the advantages of rapid fertilizer efficiency, high utilization rate, saving of fertilizer, significant effect and simplicity. However, in the specific operations, scientific and reasonable measures must be taken to avoid waste and cause damage. The following ten points must be mastered. 1. Fertilizer varieties are suitable for many types of fertilizers, but some are suitable for foliar spraying, and some are not suitable for foliar spraying. Such as urea, potassium dihydrogen phosphate, calcium superphosphate leachate, potassium sulfate, borax, zinc sulfate, etc. can be sprayed, while some chlorine-containing, volatile and insoluble fertilizers (such as ammonium chloride, ammonium bicarbonate, Calcium, magnesium, phosphate, etc.) cannot be sprayed on the surface. 2. The spraying concentration should be suitable for the top dressing. According to different fertilizers, the spraying should be carried out according to the corresponding concentration. The concentrations of different fertilizers sprayed were: 1% to 3% urea, 0.3% to 0.5% potassium dihydrogen phosphate, 0.1% to 0.2% borax, 0.2% to 0.4% zinc sulfate, and 2% to 4% of superphosphate leaching solution. Ammonium sulfate 0.2% to 0.3%. 3. To spray targeted crops and soil-based fertilizers in accordance with the principle of lack of supplements. If the seedlings are thin and yellow, indicating nitrogen deficiency, nitrogen injection should be the main method; if the seedlings are in general, spraying with nitrogen and phosphorus should be the main solution; if the seedlings are long green, they should be sprayed with phosphorus and potassium. 4. To spray different crops in the critical period of crop needs fertilizer for fertilizers of different periods, need to be flexible, such as wheat should be sprayed after full-fat, soybean, peanut, rape should be at the beginning and full bloom Spraying separately, corn and sorghum should be sprayed during the grain filling period, and sweet potatoes and potatoes should be sprayed during fruit expansion. 5. The spraying site must be the absorption capacity of the leaves. The new leaves are stronger than the old leaves. For monocotyledons, such as wheat, the stomata on the leaves are almost the same, but the leaves are easy to be stained with fertilizer solution, so the front of the sprayer should be The main; and dicotyledonous plants, such as soybeans, cotton, stomata more than leaf surface, and the back of the sponge tissue suction capacity is strong, so the front and back of the leaf should be sprayed. 6. The amount of liquid to be sprayed should be sufficient. The specific dosage should be determined according to the crop type and growth period. The general requirement is that the fertilizer solution will flow from the leaf surface but not flow down. It is generally best for every 667 square meters (1 mu). Fertilizer volume 50 to 70 kg. At the same time in the whole growth period to spray 2 to 3 times is appropriate, separated by time of 7 to 10 days is appropriate. 7. To choose fertilizer time outside root dressing in order to perform best in humid weather. Sunny days should be sprayed before 10 o'clock in the morning and after 4 o'clock in the afternoon. In cloudy and windless weather, it can be sprayed all day. 8. One-spray and multi-effect spraying of two or more kinds of fertilizers and pesticides can improve the work efficiency, and has the advantages of saving fertilizer and saving medicine. However, when mixing, care should be taken not to mix acidic and alkaline fertilizers and pesticides that have antagonism. 9. Fertilizer spray should be even and considerate. General fertilizers are mostly in the form of solids. When used, they should be fully stirred to allow them to be completely dissolved. The spraying should be even and thorough, do not leak spray, but it can not be repeated spray, so as not to cause fertilizer damage. If yellow spots and focal edges appear on the leaves, normal growth of the crop will be affected. 10. To add active agent Add a small amount of active agent (such as silicone, neutral soap, washing powder) to reduce the surface tension of fertilizer solution, which is conducive to the spread and depth of fertilizer solution, can improve the spraying effect. Anti Bird Netting,Anti Bird Net For Balcony,Anti Pigeon Net,Anti Bird Mesh Changzhou Satidi Import and Export Co., Ltd. , https://www.guanjiejts.com