Detailed Explanation of the Eight Major Taboos in Watermelon Fertilization
Because watermelon has a relatively short growth cycle and a large growth volume, its demand for fertilizer is also relatively large. However, if fertilization is not done carefully, problems such as difficulty in setting fruit, deformed appearance, poor taste, and low yield can easily occur. Below is a detailed explanation of the eight major taboos in watermelon fertilization for everyone's reference.
1. Taboo in watermelon fertilization: not understanding the principles
The general principle of watermelon fertilization is to apply heavy organic fertilizer, a moderate amount of nitrogen fertilizer, steady phosphorus fertilizer, increased potassium fertilizer, combined application of the three elements nitrogen, phosphorus, and potassium, and an appropriate supplementary application of medium and trace element fertilizers.
2. Taboo in watermelon fertilization: fertilizing on rainy days
During rainy weather, humidity is high, soil water content is high, fertilizer is easily lost, and vines and leaves grow excessively, with tender leaves and brittle vines, making plants prone to pests and diseases.
3. Taboo in watermelon fertilization: fertilizing during drought
Fertilizing when the soil is dry causes the aqueous solution in root cell cytoplasm to seep outward, causing plasmolysis, leading to physiological water loss and wilting of watermelon vines and leaves, until the plant dies. Therefore, in dry weather and when soil water content is low, irrigation or watering should be done first to moisten the soil before fertilizing.
4. Taboo in watermelon fertilization: fertilizing too close to the roots
As watermelon vines extend, the root system gradually expands. If fertilizer is applied close to the roots, the fertilizer not only cannot be fully absorbed and utilized, but root burn can also occur. Therefore, fertilization should follow vine extension, gradually being applied from near to far at a considerable distance from the plant, so as to facilitate absorption by the watermelon root system. Generally, a distance of about 15 cm from the main root is required.
5. Taboo in watermelon fertilization: applying chlorine-containing fertilizers
Topdressing for watermelon should not use chlorine-containing chemical fertilizers, such as ammonium chloride and potassium chloride. Applying chlorine-containing fertilizers affects sugar accumulation and makes the melon taste bland.
6. Taboo in watermelon fertilization: fertilizing on the surface soil layer
In summer, temperatures are high and thunderstorms are frequent. If fertilizer is applied to the surface soil layer, not only are nutrients easily evaporated, but they are also washed away by rainwater. Fertilization should be done by digging holes between two plants for deep application, followed immediately by covering with soil, to improve fertilizer efficiency.
7. Taboo in watermelon fertilization: applying a large amount of nitrogen fertilizer alone
Watermelon fertilization places the greatest emphasis on the coordination of nitrogen, phosphorus, and potassium. If a large amount of nitrogen fertilizer is applied alone, the plants are very prone to excessive vegetative growth, which is unfavorable for flowering, fruit setting, and fruit development. According to research, before fruit setting, watermelon is mainly dominated by nitrogen nutrition, and after fruit setting, potassium uptake increases sharply; at the stage when the fruit loses its hairs, nitrogen and potassium amounts are basically equal; during the fruit enlargement stage, uptake reaches its peak; and at the fruit ripening stage, nitrogen and potassium uptake decreases significantly, while phosphorus uptake increases relatively. The ratio of the three elements nitrogen, phosphorus, and potassium should be 3.8:1:2.8 at the seedling stage, 3.6:1:1.7 at the vine extension stage, and 3.5:1:4.6 at the peak growth stage of the fruit.
8. Taboo in watermelon fertilization: applying too much human and animal manure and urine
Applying too much human and animal manure and urine can easily cause excessive vegetative growth of the plants, making fruit setting difficult, and resulting in thick rind and sour taste.