Detailed Explanation of Rice Super-High-Yield Intensive Cultivation Technology

I. Technical Characteristics

Compared with traditional high-yield cultivation techniques, the rice super-high-yield intensive cultivation technology system has the following characteristics.

1. Early transplanting of young seedlings. The intensive cultivation technology allows transplanting of 2-3 leaf-age seedlings in winter fallow fields or winter paddy fields, and 3-5 leaf-age seedlings in double-cropping fields. Compared with traditional techniques, transplanted seedlings are reduced by 2-4 leaves, which is conducive to early growth and rapid development, and improves the tillering-to-panicle rate.

2. Sparse planting for strong plants. The intensive cultivation technology uses sparse planting in the main field, with 6000-9000 hills planted per mu, which is 5000-7000 hills fewer than traditional techniques, conducive to tillering and individual plant growth, forming a population structure favorable for high yield, and promoting large panicles with many grains.

3. Moisture for strong roots. Compared with traditional techniques, the intensive cultivation technology implements irrigation primarily based on moist irrigation after transplanting, greatly reducing irrigation water consumption, and conducive to root growth and development.

4. Controlling tillers for strong stems. The intensive cultivation technology places greater emphasis on field drying at the mid-stage, controlling the occurrence of ineffective tillers and promoting the growth of effective tillers, achieving strong stems and large panicles.

5. Sufficient fertilizer for high yield. Rice super-high-yield intensive cultivation requires appropriately increased fertilizer application. Based on soil fertility levels and yield requirements, pure nitrogen applied per mu is increased by 1-5 kg compared with conventional techniques, with emphasis on applying organic fertilizer. In terms of fertilization methods, the principle of “reduce early, increase late; increase panicle and grain fertilizer amounts” is adopted. Base fertilizer is mainly organic fertilizer, supplemented by quick-acting chemical fertilizers. Sufficient topdressing and panicle fertilizer are applied to meet the nutritional requirements for high yield.

During the demonstration and extension process, when combined with techniques such as no-till paddy fields and intercropping of hybrid and glutinous rice, the technical advantages become more obvious and the economic benefits higher.

II. Main Cultivation Technical Regulations

1) Selecting suitable super-high-yield varieties

High-yield, high-quality hybrid rice combinations with relatively strong tillering ability, large panicle type, relatively strong lodging resistance, and good adaptability should be selected.

2) Cultivating age-appropriate strong seedlings

It is recommended to use plastic soft trays (or no trays) for dry seedling raising, or moist heat-preservation seedling raising. Seeding rate should be determined according to seedling age, with fine sowing, strengthened fertilizer and water management, to cultivate age-appropriate strong seedlings.

3) Ensuring transplanting quality

1. Field preparation

After winter fallow fields or previous crops are harvested, promptly release water, soak the field, plow, harrow fine and level, then apply base fertilizer, harrow once more, and retain shallow water for transplanting. It is recommended to make raised beds with ridge cultivation, with bed surface width of about 1.5 m, furrow width of 0.2-0.3 m, and furrow depth of 0.1 m.

2. Timely early transplanting

In double-cropping fields, timely transplant 2-5 leaf-age seedlings. For paddy fields after previous crop harvest, no-till can be implemented to seize the farming season and save costs.

3. Reasonable sparse planting

Use line-marked transplanting, or line-marked bed making (ridge cultivation) for transplanting, to improve ventilation and light conditions of the field population.

For paddy fields with lower soil fertility or low fertilization levels: transplanting spacing of 8-9 cun × 8-9 cun (0.8-1 wan hills per mu).

For paddy fields with medium soil fertility or medium fertilization levels: transplanting spacing of 1-1.2 chi × 1.2 chi (4500-5000 hills per mu).

At the same time, variety characteristics should also be considered. For high-yield rice varieties with large panicles and many grains, density should be sparser; conversely, density should be appropriately increased.

4. Reforming transplanting methods

Plant three seedlings per hill in a triangular arrangement, with row spacing of 1-1.2 chi, hill spacing of 1-1.2 chi, and seedling spacing of 2-3 cun. Single hills with 3 seedlings form a small triangle, and staggered hills between rows form a large triangle cultivation pattern, achieving sparseness within density and density within sparseness, thereby promoting tillering and increasing the number of effective panicles.

4) Strengthening field management

1. Balanced fertilization by formula

(1) Fertilizer types: For rice super-high-yield intensive cultivation, the combined application of organic fertilizer and chemical fertilizer gives the best yield-increasing effect, and also has effects such as improving fertilizer utilization rate, increasing soil fertility, and improving rice quality. The proportion of organic fertilizer accounts for about 30% of the total fertilization amount.

(2) Fertilization methods and amounts: Determined according to paddy field fertility and yield requirement levels, implementing stable nitrogen and increased potassium. Generally, apply 10-12 kg pure nitrogen per mu, with N:P:K ratio of 2:1:2. For fields with medium fertility, apply 40 kg of “Qiqushan” brand soil-testing formula fertilizer per mu as base fertilizer. Apply panicle fertilizer based on seedling condition; if field growth is vigorous, apply less or later; conversely, apply earlier or more. Generally, after field drying and re-watering, apply 4-6 kg urea and 5-7.5 kg potassium chloride per mu. Universally apply grain fertilizer; to improve seed-setting rate and grain weight, 5-7 days after heading, apply 1 g of “920” plus 1 bag of Shuofeng “481” diluted in 50 kg water per mu for spraying. Overall, the requirement is to achieve “vigorous early stage (promoting early and rapid tillering, reaching sufficient tillers early), controllable mid-stage (reducing the number of ineffective tillers, promoting effective tiller growth), and stable late stage (nourishing roots and preserving leaves, promoting grain filling).”

2. Water-saving high-yield technology

(1) Regreening stage: Transplant and regreen with shallow water (about 2 cm).

(2) Early growth stage (tillering stage): In the early tillering stage, maintain moist or shallow water alternating dry-wet irrigation (i.e., irrigate 2-3 cm, then drain and expose the field for 1-2 days, then irrigate again, repeating this cycle) to promote early and rapid tillering. In the late tillering stage, “dry the field based on seedling condition,” i.e., when the total number of tillers in the entire field (main stems plus tillers) reaches 180,000-200,000 per mu, drain and dry the field. If growth is vigorous or drainage is difficult, start drying the field when the total number of tillers reaches 150,000-180,000 per mu to reduce the number of ineffective tillers, improve the tillering-to-panicle rate, and promote the growth of large tillers.

(3) Mid-growth stage (young panicle differentiation to heading and flowering): Maintain shallow water (about 2 cm) irrigation to promote large panicles; strictly avoid drought.

(4) Late growth stage (grain filling and ripening stage): Alternate dry-wet irrigation, nourish roots and preserve leaves to promote grain filling. Stop water 5-7 days before maturity; strictly avoid stopping water too early, which affects yield and quality.

3. Timely weeding

The following three methods can be adopted:

(1) Cultivation and weeding: Based on weed occurrence, during the tillering stage, combine with the application of tillering fertilizer to carry out 2-3 times of manual weeding and cultivation.

(2) Chemical weeding: Generally carried out 7-10 days after transplanting, maintaining a 4-5 cm water layer in the field. Apply 13 g of Nongdeshi per mu, spray with water or mix with fine soil and broadcast. Do not drain water within 7 days after application. Do not use chemical herbicides not permitted by national standards.

(3) Rice bran weeding: After seedlings regreen and survive, drain and expose the field, evenly broadcast 100 kg of rice bran per mu to cover the field surface. Before broadcasting, spray water on the rice bran and mix until it does not form a ball when squeezed by hand, so that the rice bran does not float on the water surface in the field but evenly covers the soil surface. Five days after applying rice bran, the field water becomes turbid; after 10 days, the soil surface appears as a white thin paste. Thereafter, implement moist management. This can effectively prevent weed growth.

4. Integrated pest and disease control   

(1) First-generation stem borer and leaf blast control: From late May to early June, apply 8 g of 40% Fuge or 60 g of 90% Shachongdan plus 30 g of 75% tricyclazole wettable powder per mu to control first-generation rice stem borer and prevent leaf blast. For fields with leaf blast occurrence, apply 100 g of 40% Fuji No. 1 per mu.

(2) Second-generation stem borer and neck blast control: From late July to early August, the booting to breaking-head heading stage is the critical period for controlling second-generation rice stem borer, panicle neck blast, sheath blight, and rice false smut. Following the principle of applying pesticide first to fields that break head and head earlier, apply 80 g of 13% Daojie (Chun. Sanhuan) or 30 g of 75% tricyclazole plus 20 mL of 30% Aimiao or 20 mL of 30% Jiemiao EC plus 8 g of 40% Fuge or 80 mL of chlorpyrifos EC per mu to control panicle neck blast, rice false smut, sheath blight, and second-generation stem borer.

(3) Rice planthopper, rice leaf roller, and rice skipper control: The above pests are sporadic late-stage rice pests in our county, generally occurring in early to mid-August. Apply 5 g of Actara or 16 g of 20% Yipaojing (imidacloprid) plus 100 mL of 50% dichlorvos per mu to control rice planthopper; apply 10 g of 20% Kangkuan or 8 g of 40% Fuge per mu to control rice leaf roller and rice skipper.