Detailed Explanation of the Key Points of the "Three Supers" Rice Cultivation Technique

I. Select suitable varieties

Adapt to local conditions and choose high-quality varieties that can mature normally and safely in the local area, with moderate tillering, relatively large panicles, relatively high grain weight, strong stress resistance and disease resistance, upright leaves, a compact plant type, and outstanding high-yield performance.

II. Sow early at the right time and sow sparsely to cultivate strong seedlings

(1) Seedling raising preparation

1. Seedbed preparation

① Seedbed selection: choose a pollution-free, flat and loose, fertile soil, good water-holding, wind-sheltered and sunny plot as a dedicated seedling field.

② Land preparation and arching: in order to achieve ultra-early sowing, prepare the seedbed soil and set up the frame the previous year, cover with plastic film in early to mid-March to promote thawing and raise soil temperature, shallowly plow the seedbed land 10 cm, and rake it level and fine. Make the bed 10 days before sowing, and dig a 13 cm deep ditch around the seedbed.

The bed surface should meet the requirements of "firm, level, clean, and straight." Firm means the bed surface is settled and does not sink underfoot; level means the bed surface is flat with no high or low spots; clean means the bed surface has no stubble or debris; straight means the seedbed is neat with four vertical sides.

2. Nutrient soil preparation

Use 20% mountain humus soil or peat soil plus 70% fertile upland field soil (never treated with herbicides), add 10% sieved decomposed pig manure, prepare 2000-2500 kg of mixed soil per hectare, requiring about 450-500 seedling trays (561-hole trays).

Choose sunny weather and when the seedbed soil moisture is suitable, sieve with a 50-mesh sieve. Suitable moisture means a water content of 10-15%, and the fine soil can be formed into a ball by hand and breaks apart when dropped. Mix the sieved fine soil with the locally promoted high-quality, safe, and reliable seedling nutrient conditioner (mix evenly according to the instructions), so that acid adjustment, fertilization, and disinfection are completed in one step. An appropriate amount of fungicide for preventing damping-off can be added to the nutrient soil to prevent the occurrence of damping-off. After mixing evenly, cover with agricultural film and set aside for later use. Separately prepare 600 kg of unfertilized sieved fine soil as covering soil for the seeds (covering soil).

3. Seed preparation

① Seed quantity: use about 40 kg of selected seeds per hectare.

② Seed treatment: First, sun the seeds. Before sowing, choose sunny and warm weather and sun the seeds for 2-3 days, turning them 3-4 times each day, to promote enzyme activity inside the seeds, strengthen metabolism, enhance the seeds' water absorption capacity, and improve seed germination vigor. Second, select the seeds. Use salt water with a specific gravity of 1.13 to select seeds and eliminate shriveled grains, then rinse clean with clear water. Third, disinfect the seeds. Use new agents to disinfect the seeds, turning them up and down twice a day, and soak the seeds to prevent the occurrence of bakanae disease. Fourth, germinate the seeds. Place the soaked seeds under conditions of 30-32°C to break the hull; when about 85% of the seeds have broken the hull, lower the temperature to 25°C for controlled-temperature germination, keeping the sprouts at about 1.5 mm; after germination, air-dry the sprouts for 6 hours in preparation for sowing.

(2) Sowing

1. Sowing period

Finish sowing before April 10; the earlier the better relatively, and it is suitable when the seedbed soil has thawed to 15-20 cm.

2. Tray placement and sowing

Water the seedbed thoroughly with bottom water and disinfect the soil to make it soft. Place the trays tightly, and use a seeder or manual dibbling, with 2-3 seeds per hole. After covering with soil, carry out closed weeding and cover with film.

(3) Seedbed management

1. Temperature management

From sowing to emergence, increase covering and keep warm at 30°C. When 80% have emerged, remove the plastic film to prevent scalding. During the 1-leaf stage, do not exceed 30°C; during the 2-leaf stage, do not exceed 25°C; during the 3-leaf stage, do not exceed 20°C. Harden the seedlings 3-5 days before transplanting to adapt to the outside temperature. When the nighttime minimum temperature is above 10°C, ventilate day and night.

2. Water management

Before emergence, maintain seedbed soil moisture. Before emergence and during the 3-leaf stage, control watering; after the 3-leaf stage, water timely according to conditions.

3. Pest and disease control

3 days before transplanting, apply a "send-off fertilizer" once, applying 30 g of ammonium sulfate per square meter, combined with watering, and at the same time spray a rooting powder solution to accelerate greening after transplanting.

Standards for strong seedlings: The standard for multi-tillered strong seedlings is seedling age ≥40 days, leaf age ≥5, with ≥2 tillers, plant height ≥15-17 cm; their appearance is stocky and short-strong, with thick and somewhat flat bases, neat and multi-tillered, tall plants, and elastic.

III. Transplant at the right time and strengthen paddy field management

(1) Rational fertilization

1. Fertilization level

Adopt formula fertilization for rational fertilizer use. The fertilization amounts are: high-quality farmyard manure 30 cubic meters/hectare, pure nitrogen 120-150 kg/hectare, pure phosphorus 55-75 kg/hectare, pure potassium 60-80 kg/hectare, available silicon 15 kg/hectare, and apply zinc fertilizer in an appropriate amount according to actual conditions.

2. Fertilization method

Before plowing or harrowing, apply 50% of all nitrogen fertilizer, all phosphorus fertilizer, 60% of potassium fertilizer, and all silicon fertilizer; tillering fertilizer should apply 30% of nitrogen fertilizer; panicle fertilizer should apply 20% of nitrogen fertilizer and 40% of potassium fertilizer. Zinc fertilizer can be used as base fertilizer or topdressing, but only one method may be chosen, and it should be applied in alternate years.

(2) Rational transplanting

Transplanting time: May 15-25 is suitable, and seedlings should be transplanted with tillers.

Transplanting density and spacing: wide rows and ultra-sparse planting. According to variety characteristics and the degree of strong seedlings, advocate 36-17 cm, with 2-3 seedlings per hole.