1. Technical points
(1) Cultivate standardized strong seedlings
Cultivating standardized and strong seedlings is the most fundamental and precondition core technology for high-quality and high-yield cultivation of rice pot seedlings.
1. Strong seedling standard. The key to machine-transplanted pot seedlings is to cultivate standardized strong seedlings. The seedling age is about 25-30 days, the leaf age is about 5.0, the seedling height is 15-20cm, the stem base width of a single plant is 0.3-0.4cm, the average number of tillers per plant is 0.3-0.5, and the number of white roots per plant is 13-16. Seedling hole rate: conventional rice ≥95%, hybrid rice ≥90%. Average number of seedlings per hole: 3-5 seedlings for conventional japonica rice, 2-3 seedlings for hybrid japonica rice, and about 2 seedlings for hybrid indica rice. Tiller rate per plant: conventional rice ≥ 30%, hybrid rice ≥ 50%.
2. Make flat seedling boards. According to the size and specification of the bowl and pan, furrows are dug according to the furrow width of 1.6m, the furrow width of 0.35-0.40m, and the furrow depth of 0.2m. It is required that the furrow surface should be flat, that irrigation and drainage should be separated, that inner and outer ditches should be matched, and that both irrigation and drainage can be achieved. The whole field has been watered many times to check the level, and the height difference does not exceed 1cm. Spread fine-pored gauze (<0.5cm×0.5cm) on the border surface before placing the tray to prevent the root system from growing into the bottom bed soil and causing the soil to stick to the bottom of the seedling tray when the tray is opened.
3. Precise sowing. It is advisable to sow 4-5 grains of conventional japonica rice per hole, and 3-4 seedlings can be grown; the amount of dry seeds per plate is about 60g. It is advisable to sow 3 grains of hybrid japonica rice per hole, and 2-3 seedlings can be grown. For hybrid indica rice, sow 2-3 seeds per hole, and 2 seedlings can be grown.
4. Darken Qi Miao. Darkening technology is used in seedling raising, which is beneficial to the whole seedlings. Stack the sown seedling trays outdoors. When stacking, the upper and lower seedling trays are staggered to ensure that the hole of the upper seedling tray is placed on the groove of the lower seedling tray, and there is a certain gap between each stack of seedling trays. . The bottom of each stack of the bottom plate is supported by things or the bottom seedling plate is an empty seedling plate, and the topmost plate of each stack is an empty seedling plate. After the stacking of the seedling trays is completed, cover the surroundings of the seedling trays with black plastic cloth in time. After 3-5 days of darkening, the plastic sheet can be removed when the seedlings are fully grown and the incomplete leaves are grown.
5. Arrangement. Place the darkened plastic trays side by side on the furrows along the length of the seedling trays, and place the trays closely together, so that the seedling trays and the furrows are close to each other and cannot be hung empty. The plate on the seedling board needs to be leveled and aligned.
6. Drought and chemical control. Drought and strong seedlings. In the 1-3 leaf stage, water should be replenished in time when there is little dew on the tip of the leaf in the morning on a sunny day; after the 3-leaf stage, the seedlings will roll their leaves and replenish water in the evening of the same day; after the 4-leaf stage, pay attention to water control to promote root packing; 1 day before transplanting, Moderately water the seedlings well.
Twice chemically control strong seedlings. For the first time, the nutrient soil with seedling-strengthening agent in the hole of the seedling tray can dwarf and strengthen the seedlings; for the second time, at the 2-leaf stage of the seedlings, 4g of 15% paclobutrazol powder can be used for every 100 seedling trays, and sprayed with water. The spray should be even.
(2) Precise machine insertion
The row spacing of the rice pot seedling transplanter has two types: equal row spacing (row spacing 33cm) and wide and narrow rows (wide row 33cm, narrow row 27cm, average row spacing 30cm).
For single-season rice with large spikes, a rice transplanter with a row spacing of 33 cm should be selected. Conventional japonica rice generally adopts a plant spacing of 12cm, inserts 16,800 holes per mu, 3-5 seedlings per hole, and basic seedlings 60,000-70,000/mu. Hybrid japonica rice is planted with a plant spacing of 14 cm, 14,400 holes per mu, 2-3 seedlings per hole, and 30,000-40,000 seedlings per mu. Indica hybrid rice has strong luxuriance, and can be planted with a plant spacing of 16cm, 12,600 holes per mu, 1-3 seedlings per hole, and about 30,000 seedlings/mu.
Medium and small panicle varieties of single-cropping rice and double-cropping rice varieties should choose wide and narrow row transplanters (average row spacing 30cm). Conventional japonica rice generally adopts a plant spacing of 12cm, inserts 18,500 holes per mu, 4-5 seedlings per hole, and 70,000-90,000-90,000 seedlings per mu. The hybrid rice adopts a plant spacing of 14cm, and 15,800 holes per mu are inserted. Among them, there are 3 seedlings per hole for hybrid japonica rice, and the basic seedlings are 40,000-50,000/mu; for hybrid indica rice, there are 2-3 seedlings per hole, and the basic seedlings are about 40,000/mu.
Guaranteed to be accurate. The insertion depth is consistent, and the planting depth is controlled within the range of 2.5-3.0cm.
(3) Precise fertilization
The suitable ratio of basal tiller and ear fertilizer for nitrogen fertilizer is 6:4, and the suitable ratio of nitrogen fertilizer for basal tiller and ear fertilizer is 7:3 under the condition that the previous crop straw is fully returned to the field. Machine-transplanted rice in pot seedlings is applied early and re-applied tillering fertilizer, and generally re-applied 3-5 days after transplanting. In the middle and late stages of growth, flower-promoting fertilizers should be applied at the inverted 4-leaf or inverted 3-leaf stage. Phosphate fertilizers are generally used as base fertilizers; 50% of potassium fertilizers are used as base fertilizers, and 50% are used as flower-promoting fertilizers.
(4) Scientific management of water
Seedlings are planted in thin water, tillering in shallow water, enough for seedlings to jointing stage to be lightly placed in the field in stages, from jointing to heading stage “water-wet-dry” alternates, and grouting and firming stages are alternated “shallow-wet-dry”.
2. Suitable area
It is suitable for all major rice producing areas in my country.
3. Matters needing attention
In the process of demonstration and promotion of this technology, master the standardized seedling cultivation method of machine-transplanted pot seedlings, especially the seedling control (seedling number), water control, chemical control and darkening technology, so as to improve the pot hole seedling rate. Lay fine-pored gauze (cut root net) before placing the plate, which is convenient for starting the plate. Clean up the soil between the holes when sowing and covering the soil, and the water in the seedling field period cannot overflow the surface of the seedling plate, so as to prevent the seedlings between the holes from stringing roots and affecting machine transplantation.
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