The main branches and leaves of yam during the seedling stage and vine-rejection period are nitrogen-based fertilizers. After budding, they enter the period of prosperous growth. Underground tubers begin to swell, requiring a large amount of fertilizer. This is a critical period for fertilization, and NPK should be used in conjunction with potassium fertilization. First, base fertilizer. Select a good field, apply 2,000 to 4000 kg of farmyard manure and 60 to 80 kg of compound fertilizer per acre as basal fertilizer, then plow the soil for 30 centimeters and mash it. Second, top dressing. The seedling stage is dominated by nitrogen fertilizer, applying 10kg-15kg high-nitrogen-potassium compound fertilizer per acre. In early July, high-nitrogen-potassium compound fertilizer is applied in an amount of 20 kg to 25 kg per acre, and 0.25% potassium dihydrogen phosphate is sprayed once. From the beginning of July, it can spray 0.25% potassium dihydrogen phosphate 2 times -3 times, in early August, 20 kg - 30 kg of NPK compound fertilizer per acre. Tuber filling usually does not use soil topdressing, spraying 0.25% potassium dihydrogen phosphate once to extend the vine growth time. Disposable Face Mask,Disposable Sterile Face Mask,Medical Surgical Mask,Medical Disposable Face Masks Jiangyin Huashi Medical Equipment Co.,Ltd , https://www.medicalwellcare.com