Key Points of Topdressing Techniques for Watermelon Cultivation in Summer and Autumn

For watermelons grown in summer and autumn, the growth period is short, so fertilizer requirements must be concentrated. Both base fertilizer and topdressing should be based mainly on quick-acting fertilizers, with nitrogen, phosphorus and potassium fertilizers properly combined and supplied in sufficient amounts. The base fertilizer is applied during land preparation, with 75 to 100 kg of decomposed cake fertilizer and 30 to 40 kg of superphosphate per mu, or 40 to 50 kg of a nitrogen-phosphorus-potassium three-element compound fertilizer.
After the vines spread, in combination with intertillage, apply 15 to 20 kg of diammonium phosphate and 5 to 7.5 kg of potassium sulfate per mu, or 20 to 25 kg of a three-element compound fertilizer and 10 kg of urea. You can also spray 0.2% to 0.3% potassium dihydrogen phosphate in combination with pest and disease control, which can improve quality.