Currently, there are various ways of rice seedling cultivation, including wet seedling cultivation, dry seedling cultivation, field seedling cultivation and factory seedling cultivation. Different cultivation methods, different seedling planting ages, and different seedling nursery sites are selected, and the way of seedling nursery also differs. Here we mainly introduce 4 more common seedling nursery methods and technical points.
1. Wet seedling nursery technology points
In the seedling field, open furrows, compartment sowing, mud tread grain, film cover, after sowing, wet or shallow water irrigation is the main method of seedling. Use sparse sowing, heat preservation and germination sowing, and determine the suitable sowing period by the safe spike flowering period and suitable rice planting age. In the low temperature and rainy weather of early rice, after wet seedling sowing, it is necessary to cover with film, mulch, non-woven fabric, etc. to prevent rotten seeds and improve seedling quality.
The main points to note: (1) the appropriate temperature germination: soak sufficient water grain seeds with a bag set, to ensure that the air required for the germination of grain seeds, indoor insulation in the evening, the appropriate temperature for germination is 30 ℃, too low germination slow, too high will burn buds, wait for the seeds to show white (grain seeds germination) can be sown. (2) Conventional wet nursery: before leaf emergence, the border surface is not watered, and it is moist; after leaf emergence, shallow water is diligently irrigated, so that water can be used to regulate temperature, fertilizer and promote sprouting. (3) With greenhouse or small arch, from sowing to 1 leaf 1 heart period to cover the film insulation, the temperature inside the film is 26-31 ℃, sunny days at noon should be uncovered at both ends of the film ventilation, to avoid the temperature is too high burn seedlings, morning and evening and then sealed insulation. 1 leaf 1 heart after gradually refining seedlings. 3 leaves 1 heart, when the temperature is stable at 13 ℃ or more, you can choose a sunny morning to uncover the film, before uncovering the film must be irrigated to protect seedlings, to prevent the temperature Before uncovering the film, make sure to irrigate the seedlings to prevent the temperature change from affecting the seedlings.
2. The main points of dry seedling technology
Dry seedling is a kind of water-saving seedling raising method, characterized by dry land preparation and dry management, with more oxygen in the soil, developed root system and strong vitality of seedlings, fast root development and early survival after transplanting. After sowing the seedlings, the field is kept moist, and before transplanting, the seedlings are only irrigated once, so that the seedlings become hard and can be transplanted with soil.
(1) The key to dry rice seedling cultivation is the acid adjustment, disinfection and fertilization of the bed soil, which can be applied with dry seedling regulator, dry seedling nanny or strong seedling agent, all of which can play the role of disinfection, acid adjustment, fertilization, chemical control and strong seedling, simplifying the more complicated operation procedures of dry seedling seedbed production. (2) Seedling management, sowing to seedling, sealed film insulation temperature of 30-32 ℃, the temperature is higher than 35 ℃, uncover the two ends of the film to cool down. From seedling to 2 leaves 1 heart temperature 21 ℃, higher than 25 ℃ should be ventilated and cooled, depending on the moisture content of the appropriate fertilizer and watering. 3 leaves 1 heart can be uncovered after the film refining, water control and root promotion. (3) Pay attention to the control of blight, green blight and rice plague, etc.
3. The main points of field seedling breeding technology
Including seedlings with soil transplanting seedling and machine inserted rice substrate seedling, mainly using dense sowing, short seedling age, with soil shallow inserting, with the effect of saving the rice field, seed, fertilizer, labor, yield increase.
Technical points: (1) for the bed. Choose a high, flat, windward and sunny, convenient watering vacant land and field for seedbed base. Soil for the bottom of the seedbed because it does not retain water, you can lay a layer of old plastic sheeting bottom. The seedbed site is surrounded by a 10cm wide ridge made of coarse straw rope or soil, and the ridge is 20cm wide at intervals and used as a walkway. Spread 2-3cm thick river mud or 20%-30% pig manure mixed with finely crushed and sieved cooked soil on the seedling bed, and apply appropriate amount of ammonium sulfate and calcium superphosphate. (2) Sow the seeds. After the seedbed bed is leveled, watered once and smoothed, the seeds can be sown. The seeds will be soaked, sowing when dewy, so that the uniform sowing, mud does not see the day, the seeds do not overlap. After sowing, cover with fine soil or fly ash. (3) Management. Watering should be a small amount of diligent watering, to keep the border soil moist. After the seeds are green, control the water properly so that the seedlings are well rooted, and pay attention to heat preservation and frost prevention when the temperature changes to avoid dead seedlings. Stop watering 2-3 days before the seedling starts.
4. Key points of factory seedling breeding technology
Factory transplanting is a new technology developed in recent years according to the needs of machine transplanting cultivation, in which intelligent greenhouses with highly automated facilities are used for rice transplanting.
The main points of seedling breeding equipment and technology are:
(1) Pre-treatment. In addition to the working room, it includes soil sifter, fertilizer mixer, water tank, sprouting equipment, seeding tray loading and seeding equipment, seeding trays, etc. The operation of seeding tray loading and seeding, mulching and watering is automated.
(2) Seedling emergence treatment. The seedling emergence period requires a constant room temperature of 30-32°C and adopts two ways: emergence in the light and emergence in the dark.
(3) Greening treatment. The way of placing multi-layer seedling trays on the seedling tray frame and flat seedling trays in the hotbed, the way of flat seedling trays in the hotbed covers a large area, but the sprinkler can be used for watering to improve the work efficiency.
(4) "Squatting" treatment. The "squatting" stage places the seedling tray in the same way as the greening stage, and can be watered automatically.
When buying seeds, it is advisable to choose large and full seeds, which have strong germination potential. From practical cultivation, the standard of strong seedlings should be short and thick seedlings without disease spots, neat growth and strong root growth.
