Smooth progress in the application of the cotton "two-ization" technology

The cotton factory seedling raising and mechanized transplanting technology (abbreviated as the "two-ization" technology) has the characteristics of modern agriculture. It is an intensive and large-scale production technology, and also a resource-saving and environmentally friendly technology. Its core technologies are substrate seedling raising and bare-seedling transplanting. It passed appraisal by the Ministry of Agriculture in 2004 (Ministry of Agriculture achievement registration number: Nongkeguojianzi [2004] No. 0056), ranks at the international leading level among research of the same kind, and has obtained multiple national @#@78@#@, achieving productization and serialization of the technology. Last year it entered production demonstration, and this year all localities have included it in science-and-technology cotton promotion plans. Demonstration and application cover the country's main cotton-producing regions. At present, sowing and emergence in seedbeds are good, and progress is smooth, indicating that the modernization of China's cotton production has begun to take shape, and new models and new experience are being created in practice.

I. Demonstration and transformation of the new "two-ization" technology covers the country's main cotton-producing regions

This year, while steadily expanding the area in the Yangtze River basin, the "two-ization" technology has been actively advanced in the Yellow River basin cotton region and extended into the northwest inland cotton region. Demonstration sites are distributed in the cotton-producing provinces, municipalities and autonomous regions of Hunan, Hubei, Anhui, Jiangxi, Jiangsu, Zhejiang, Henan, Shandong, Hebei, Tianjin and Xinjiang. According to preliminary statistics, there are 300 demonstration counties (regiments, farms), and the area of early-spring cotton seedbed (first round) seedling raising and transplanting is expected to reach 600,000 mu, with 100,000 mu for vegetables and melons. Since early March, substrate seedling raising has already begun. In early March, the **Production and Construction Corps Agricultural Division 4 sowed, followed by Agricultural Division 7, Agricultural Division 1 and Agricultural Division 2 sowing respectively. By April 5, seedlings in the seedbeds were neat, young seedlings grew steadily, with no diseases, insects or weeds, dark green leaf color, and 2-3 true leaves. As soon as warm weather is seized, they can be transplanted into the field, advancing the growth period by more than 30 days compared with direct seeding in the field, laying the foundation for high and super-high cotton yields. In the interior, sowing began successively in early April. Owing to strengthened training, on-site demonstrations and roving guidance, and operation according to standards, seedbed emergence was neat, young seedlings grew robustly, with no disease, and early-sown seedbeds had already produced true leaves.

After nearly 4 years of demonstration, all localities have shown the following: First, the seedling formation rate in seedbeds is high, basically achieving one seedling from one seed, saving more than half the seed. Second, the seedlings are robust, with many roots, intact cotyledons, thick stems and close nodes, and moderate seedling height. Third, there is no disease, and no pest or disease control is needed. Because the substrate is soilless and free of pathogenic organisms, seeds and buds do not rot. Fourth, seedbed management is simple and convenient. Because the substrate provides complete nutrition for the seedlings, making the bed only requires adding clean river sand. During the seedling period, root-promoting agent is applied and appropriate water is supplied according to operating rules, saving much labor. The results show that the technical indicators of the "two-ization" technology have good reproducibility.

II. Innovating new models of substrate seedling raising and bare-seedling transplanting

All localities have innovated a number of new seedling raising and transplanting models. The main models include dispersed seedling raising, centralized seedling raising, comprehensive seedling cultivation, and contract transplanting.

1. Dispersed seedling raising, convenient for thousands of households. Each household raises seedlings on its own. The seedling site can be built in a sunny place in front of or behind the house, or in the field. Because substrate seedling raising is soilless, generally 3 sq m of net area can raise 1,500 plants. The seedbed area is small, saving half the land, and it suits thousands of households.

2. Centralized seedling raising, commercial seedling supply. Large-scale and factory-based production are the main forms of centralized seedling raising. Changde Kenong Company continues to use a solar greenhouse for seedling raising, with an area of 4,540 sq m, and plans to transplant 2,000 mu. Anhui Yushun Seed Industry built 5 solar greenhouses, with an area of 2,000 sq m, and plans to transplant 200 mu; Shandong Runfeng Seed Industry built 123 simple seedbeds, with an area of 2,500 sq m, and plans to transplant 200 mu; Handan, Hebei, in conjunction with the "Thousand-mu Cotton High-yield Demonstration Project," built 6 solar greenhouses in Longyao, with an area of 2,600 sq m, and plans to transplant 1,000 mu. Agricultural Division 1 built 8 greenhouses, with seedbeds of 4,000 sq m, raising 1.2 million seedlings, and plans to transplant 200 mu. Agricultural Division 4 built 8 greenhouses, with seedbeds of 5,000 sq m, and plans to transplant 200 mu. Agricultural Division 7 built 1 greenhouse, with seedbeds of 260 sq m, and plans to transplant 15 mu. Huatian Seed Industry built 1 greenhouse in Kuitun, with seedbeds of 340 sq m, raising more than 40,000 seedlings, and plans to transplant 10 mu. Factory-based and large-scale seedling raising adopts centralized seedling raising and centralized management, realizing commercial seedling supply. This is a new leap in China's cotton production.

3. Comprehensive seedling cultivation, one bed for multiple uses. Comprehensive seedling cultivation technology has begun to take shape, and its area is continuously expanding, becoming a new direction for the development of crop and vegetable seedling technology. For example, watermelon-cotton seedling cultivation in Xiangfan, Hubei; vegetable melon-cotton in Xiantao; and comprehensive seedling cultivation of tobacco and melon seedlings-cotton in Nanyang. Various vegetables enter greenhouses or solar greenhouses in late February or early March, with a seedling period of about 30-40 days, leaving the bed in late March or early April. Then early-spring cotton is raised, leaving the bed in late April for transplanting into single-crop cotton fields, and late-spring cotton seedlings are then raised for transplanting into rapeseed fields. This realizes one bed for two or multiple uses. According to a survey, Ximing Seed Industry in Xiantao, Hubei, built 2 solar greenhouses, each 280 sq m. Sowing was carried out in late February to raise peppers, tomatoes, cucumbers, bitter melons, watermelons, winter melons and eggplants, with an order unit price of 0.1 yuan. Among them, cucumbers were raised twice, and eggplants at 0.5 yuan/plant, raising 400 plants per sq m. After deducting costs of 20 yuan, the net income was 20 yuan. For one 280 sq m greenhouse, the income in one seedling season was 5,600 yuan. In the same greenhouse and on the same seedbed, 400 early-spring cotton plants per sq m were raised, at a unit price of 0.07 yuan. After deducting costs, the income per seedling was 0.03 yuan, and the early-spring cotton income was 3,360 yuan. Then late-spring cotton was raised for an income of 3,360 yuan. In one 280 sq m greenhouse, seedlings were raised 3 times within 4 months, with an income of about 12,320 yuan, and income per unit seedbed of 44 yuan per sq m.

4. Continuous seedling raising, saving costs. The Yellow River basin adopts an early-spring cotton-short-season cotton model. After the short-season cotton is harvested at @#@245@#@, mechanized transplanting is used, with one bed for two uses and low cost. At the same time, the growth period of short-season cotton is advanced by 30 days, the pre-frost boll rate reaches 90%, yield increases and quality is good, and it is welcomed by farmers.

5. Implementing mechanized transplanting, reducing labor intensity, and seizing the season. On the basis of "contract seed" and "contract seedling raising," "contract transplanting" is implemented. In the interior, bare-seedling cotton adopts mechanized transplanting, greatly saving manpower, reducing labor intensity, seizing the season, and lowering transplanting costs. At the same time, the transplanting machinery is also suitable for transplanting vegetables and flowers, with wide uses.

III. Standardizing operations, grasping key links, cultivating robust seedlings, and improving the survival rate

Because demonstrations have continuously expanded, operations have become non-standard, which is unfavorable for cultivating robust seedlings. The main problems and corrective methods are as follows:

1. Insufficient substrate thickness. When newly making a seedbed, be sure to follow the standard operating requirements and spread evenly mixed substrate to a thickness of 10 cm in the seedbed, to ensure the substrate's functions of water supply, water retention, heat preservation and nutrition during the seedling stage. If the substrate thickness is less than 10 cm, add more substrate to the bed surface before and after emergence so that the thickness reaches 10 cm.

2. Narrow row spacing, small seed spacing, and high density. Standard operation requires a sowing row spacing of 10 cm in the seedbed and a seed spacing of 1.8-2.0 cm; the row spacing can also be adjusted to 8 cm and the plant spacing to 3 cm. If the row spacing is less than 10 cm, it is recommended to remove every other row of seedlings; if there are many seedlings after emergence and the density is high, use scissors to thin the seedlings to ensure that the plant spacing reaches more than 2 cm.

3. Correct use of root-promoting agent. The first use is from visible emergence to cotyledon flattening: use 40 ml of root-promoting agent stock solution per sq m, add 4,000 ml of water as a diluted solution, and pour it at the roots of the cotton seedlings. The second use is root soaking after lifting seedlings, for 15 minutes, with 3,000 ml of diluted solution soaking 1,500 plants; if more cotton seedlings are to be soaked, a new root-promoting agent must be prepared again.

4. Seedbed management should focus on control; young stems that are 50% red indicate robust seedlings. Ventilate the seedbed in time to prevent high-temperature seedling burning and "tall-foot seedlings"; manage water according to the seedlings. Under the condition of sufficient soil moisture at sowing, the first watering is given from emergence to cotyledon flattening together with the root-promoting agent; afterward, irrigate according to seedling condition and substrate moisture. Seedling age is 25-30 days, with 2-3 true leaves and seedling height of 15-20 cm.

5. Grasp the key links of bare-seedling transplanting. Before lifting seedlings, spray the leaf surface with a leaf-preserving agent diluted 15 times; emphasize "transplant warm seedlings, not cold seedlings" and "transplant high-temperature seedlings, not low-temperature or freeze-damaged seedlings"; the transplanting depth should be deep rather than shallow; transplant cotton as one transplants vegetables, and after planting, water with "settling-in water."