Key Fertilization Techniques for Watermelon Seedlings to Survive Winter Safely
Watermelon is one of the fruits commonly eaten in summer. It is not only juicy but also very sweet, and is deeply loved by everyone. Especially in the hot summer, eating a few bites of chilled watermelon is very refreshing and thirst-quenching. The temperature is now very cold, so how can watermelon seedlings survive the winter safely? What are the key fertilization techniques?
1. How can watermelon seedlings survive the winter safely?
Improve the heat preservation and heating measures of the watermelon seedling-raising shed. Replace polyethylene film with polyvinyl chloride anti-drip film, which greatly improves the heat preservation and performance and can raise the shed temperature by 1°C~2°C. Temporary heating equipment such as a fire wall or heating furnace should be installed in the shed. Carry out artificial heating when necessary.
1. Strengthen seedling management
Within 1 week after grafting is the wound-healing stage. The shed temperature should be kept at 20°C~30°C. The grafted seedling bed should be strictly sealed for 3~6 days to maintain the relative temperature inside the bed. For the first 3 days, it must be completely shaded, with only weak scattered light allowed through. On the 4th day, gradually expose to light. After 6 days, gradually ventilate. After the 7th day, remove the shading material and increase the ventilation. At the appropriate time, spray Shifang or Huoli Carbon on the leaves to improve the ability to resist natural disasters, increase the intensity of photosynthesis, and help the grafted seedlings adapt to the normal seedbed environment.
2. Strengthen management during disastrous weather
Management during severe weather such as continuous overcast days, rain and snow, and strong cold waves is an important part of the success or failure of seedling raising. In winter, pay attention to listening to weather forecasts and take heat preservation and heating measures before the cold wave arrives.
2. What are the key fertilization techniques for watermelon?
1. Fertilization of the seedling bed
The nutrient soil used for watermelon seedling raising requires rich organic matter content, looseness, and strong water and fertilizer retention capacity.
2. Land preparation and fertilization
Applying heavy base fertilizer is the foundation for ensuring robust growth of watermelon stems and vines and high yield. After the previous crop is harvested, in combination with deep plowing and land preparation, apply 4000 kg of decomposed organic fertilizer per mu. Dig planting furrows 30 cm deep according to the specified row spacing. Apply a 10 cm thick layer of organic fertilizer at the bottom of the furrow, then 30 kg of compound fertilizer or 10 kg of urea, and 15 kg each of diammonium phosphate and potassium sulfate. Then apply another 10 cm thick layer of organic fertilizer. On the topmost layer, apply 20 kg of compound fertilizer or 10 kg each of diammonium phosphate, potassium sulfate, and urea. Mix the chemical fertilizers, organic fertilizer, and soil in the furrow evenly, level and make ridges, water promptly, and cover with plastic film and shed film.
3. Topdressing after planting
Vine-extension fertilizer
When watermelon enters the vine-extension stage, the demand for fertilizer and water gradually increases. At this time, topdressing should aim to promote vine and leaf growth and expand leaf area, but excessive vegetative growth must be prevented. Topdressing is mostly based on decomposed organic fertilizer, combined with an appropriate amount of chemical fertilizer.
Melon-swelling fertilizer
When normal young fruit grows to the size of an egg, the fruit begins to expand rapidly, and the plant's fertilizer demand gradually reaches the highest peak of the entire growth period. At this time, heavy application of melon-swelling fertilizer should be carried out to promote fruit expansion and prevent premature senescence. Topdressing should be mainly phosphorus and potassium fertilizers, with little or no nitrogen fertilizer, to avoid a decline in watermelon quality caused by excessive nitrogen fertilizer.
Rejuvenation fertilizer
After the first crop of melons is harvested, immediately apply 1 round of quick-acting chemical fertilizer. Generally, apply 15~20 kg of urea, 15 kg of potassium sulfate, and 10 kg of diammonium phosphate per mu, and combine with topdressing by watering heavily once. Through strengthened management, supplement the nutrients and water in the soil, maintain relatively strong plant vigor, and prevent premature senescence of vines and leaves.
4. Skillfully apply foliar fertilizer
Foliar spraying of fertilizer is a necessary means to make up for insufficient root absorption and to supplement plant nutrition and balance nutrients. It has the characteristics of low application cost, uniform fertilization, fast fertilizer effect, and high nutrient utilization rate.