Before the watermelon planting, apply base fertilizers such as farm manure; apply seedling fertilizers such as nitrogen fertilizer and urea; apply strong seedling fertilizers such as nitrogen, potassium, and compound fertilizer during the extension period; apply strong flower fertilizers mainly composed of phosphate fertilizer before flowering; During the fruiting period, a strong fruit fertilizer mainly composed of potassium fertilizer was applied.

1. Apply a good base fertilizer

If planting in a small area (less than 5 acres), it is recommended to choose rotted cow dung + superphosphate (general calcium) as the base fertilizer. The fertilization amount per acre is: rotted cow dung 3000-4000 kg, superphosphate 20-30 kg.

For large-scale planting (greater than 5 acres), it is recommended to choose 15-15-15 potassium sulfate type compound fertilizer + general calcium + borax as the base fertilizer. The amount of fertilizer applied per mu is: 15-15-15 potassium sulfate type compound fertilizer 50- 70 kg, normal calcium 30-50 kg, borax 1-2 kg.

2. Apply well to spread manure

Under normal circumstances, watermelon spreading manure needs to be applied 2-3 times, and the frequency of fertilization is once every 5-7 days. For the selection of fertilizers, it is recommended to use 16-16-16 potassium sulfate compound fertilizer + a large number of element water-soluble fertilizers. The amount of fertilization per mu for the first fertilization of watermelon during the extension period is: 16-16-16 potassium sulfate compound fertilizer 5-7 kg; each subsequent fertilizer application, 16-16-16 potassium sulfate compound fertilizer increases by 1 -2 kg.

3. Apply swelling fertilizer

The swelling of watermelon needs to be applied 3-4 times, and the frequency of fertilization is once every 5-7 days. For the selection of fertilizers, it is recommended to use 19-19-19 potassium sulfate compound fertilizer + a large number of elemental water-soluble fertilizers (for example: root promoting and sweetening granules) + 10-8-41 high potassium fertilizer.