Detailed Explanation of the New Technique of Rice Seedling Cultivation with Perforated Film
How to control field seedling-stage pests, root rot, and rice seedbed diseases in spring? On March 25, the Municipal Agricultural Technology Extension Station answered common questions for farmers during spring plowing, advising prevention of disasters through measures such as proper chemical treatment of seeds, controlling seedling-stage pests and diseases, and vigorously promoting seedling cultivation in medium and large sheds. It is understood that in 2009, our...
1. Advantages of seedling cultivation with perforated film① Good seedling quality. Seedling cultivation with perforated film uses natural ventilation, ventilating early, and the temperature inside the bed changes gradually. The day-night temperature difference is small, seedlings do not grow leggy, and the seedlings are uniform and strong without disease. Seedling quality is good, and the rate of healthy seedlings is high. The ratio of seedling bed to field can be increased by about 30%.
② Great yield-increasing potential. Seedlings are not shoveled and roots are not damaged; transplanted with intact roots, they root quickly, grow and develop early and fast, with more low nodes and large panicles with many grains.
③ Low production cost. Operations such as ventilation, watering, fertilizing, and spraying do not require removing the film, saving labor and effort. Discarded greenhouse film can also be perforated and used for covering, reducing production costs.
④ The method is feasible. The perforated film seedling cultivation method is simple, easy, convenient, and practical, and is conducive to promotion and application.
2. Key technical points of seedling cultivation with perforated film
Preparing nutrient soil: Choose 70% garden soil or upland field soil, add 30% decomposed farmyard manure, and sieve to obtain nutrient soil. Each bed needs 200-250 kg of nutrient soil, and 1 bag of seedling-strengthening agent with functions of nutrition, acid adjustment, disinfection, and chemical control is applied, adjusting the soil pH to 4.5-5. Preparing high-quality nutrient soil provides balanced nutrients and an acidic soil environment for the seedlings, ensuring the cultivation of strong seedlings.
Land preparation and sowing: Choose garden or upland field land to make a bed 10 m long and 1.5 m wide, oriented north-south, with fine, crumbly bed soil free of debris. Then lay soft trays or soft tray substitutes; spread nutrient soil 3-3.5 cm thick on top, water thoroughly to saturate the bottom, and prepare for seedling cultivation. After selecting good seeds, soak the seeds in chemicals to prevent rice bakanae disease, etc. The seedling cultivation time is determined by the reservoir water release time. In the Yingkou area, it is generally April 1-10, and seedling cultivation is done on sunny days. Adopt sparse sowing to grow strong seedlings, with a sowing rate of 200-250 g per sq m. Before sowing, spray the bed surface with 1 bottle (500 g) of Yumiaoling or Yumiaoqing diluted 100 times with water over 40-45 sq m to prevent rice seedling damping-off disease. After sowing and covering with soil, use seedling-bed herbicides such as Yangmiaoling for closed weeding. Then cover with plastic film to help retain moisture and ensure uniform emergence. Insert a framework on top and cover with perforated film; the plastic film can also be placed on top of the perforated film. Both film-covering methods are acceptable.
Seedling field management: Water promptly when seedlings emerge or the bed surface turns white, ensuring uniform and strong seedlings. When seedlings reach 1 leaf and 1 heart, promptly remove the plastic film and carry out natural ventilation. At this time, water on the bed surface evaporates quickly, so replenish water promptly. It is best to water once a day before the 2-leaf-1-heart stage, and thereafter appropriately reduce watering frequency according to actual conditions. To effectively prevent rice seedling damping-off disease, it is best to apply Yumiaoling or Yumiaoqing once more at the 1-leaf-1-heart or 2-leaf-1-heart stage. After the 3-leaf stage, promptly apply nitrogen fertilizer to promote seedling growth, with each application not exceeding 50 g per sq m, using a 100-fold diluted liquid fertilizer. The plastic sheeting can be removed 10 days before transplanting.
3. Issues to note in seedling cultivation with perforated film
① The perforated film for seedling cultivation has a hole diameter of 1 cm and a hole spacing of 3 cm x 3 cm. Too dense holes are unfavorable for heat and moisture retention, while too sparse holes are unfavorable for ventilation.
② Around the bed, ridges 5-10 cm higher than the bed surface and 20 cm wide should be set up to facilitate irrigation and operations.
③ Operations such as spraying, watering, irrigation, and fertilizing do not require removing the plastic film and can be carried out directly on top of the perforated film.
④ The first green-turning irrigation should be done early rather than late.
⑤ During ventilation, if low temperatures or cold waves occur, promptly cover with plastic film to retain heat or irrigate to prevent low-temperature chilling injury. If high temperatures cause the bed temperature to exceed 30°C, appropriately remove the film for ventilation to keep the bed temperature at around 25°C, so as to avoid leggy growth and reduced seedling quality. ⑥ If seedlings grow weakly, methods such as uncovering by day and covering by night and appropriately delaying film removal can be adopted to promote seedling growth.