Detailed Explanation of the Key Technical Points of Rice Field Management
During the growth process of rice, every stage is relatively critical. After transplanting is completed, the rice enters the field management stage. What are the key technical points of rice field management?
1. Seedbed stage management
On the 2nd-3rd day after sowing and covering with film, promptly check the moisture of the seedbed surface. On the 5th-6th day, open the film at both ends for ventilation and cooling to prevent high-temperature damage to the seedlings. When the young seedlings reach the two-leaf-one-heart stage, remove the film. After removing the film, irrigate promptly to protect the seedlings. After 2-3 days, apply 4-5 kg of urea per mu for the first topdressing. After one week, apply 8-10 kg of urea per mu for the second topdressing (if using machine transplanting, fertilize reasonably according to the growth of the young seedlings). Prevent and control seedling blast in a timely manner.
2. Rice field management
1. Transplant at the right time and plant at a reasonable density. Generally, the most suitable transplanting time is from late April to early May. The most suitable seedling age is 35-40 days. For machine transplanting, the transplanting density is 18,000 clumps per mu; for manual transplanting, the most suitable density is 20,000-25,000 clumps per mu.
2. Right after transplanting, the rice seedlings must be ensured an adequate water supply. Establish a water layer immediately, but avoid flood irrigation that is too large or too small. Shallow irrigation should be the main method. The water layer depth should preferably be half the seedling height, and at most not exceed 2/3 of the seedling height. It must not cover the seedling heart. Such a water layer can not only prevent excessive transpiration of leaf moisture that leads to seedling wilting but also play a role in moisture retention, preventing low nighttime temperatures from causing frost damage to the seedlings.
3. When the rice seedlings begin to turn green, release some of the water and maintain a shallow water layer, with the depth controlled at about 3-5 cm. Such shallow water has good permeability, helps raise water temperature and soil temperature, and can effectively promote the root development of the seedlings. Roots emerge quickly, many new roots develop, and the seedlings can also tiller early. In addition, after the seedlings turn green, intermittent irrigation can also be adopted: irrigate once with 3-5 cm of shallow water, then let it dry naturally. When there is water in the pits and depressions in the field but no water on the field surface, irrigate again, and repeat the cycle.
4. After turning green, rice enters a rapid growth period. Due to the continuous development of the root system and the increase in the number of tillers, the demand for nutrients shows a continuously increasing trend, so the fertilizer amount must also continuously increase. Moreover, at this time the soil temperature is still relatively low, the nutrients in the soil have not been fully released, and because the base fertilizer is applied throughout the layer, the roots are in the surface soil, making it very easy for nutrient deficiency to occur and affect development. Tillering fertilizer should be applied in a timely manner, mainly nitrogen fertilizer, accounting for about 1/3 of the fertilizer amount for the entire growth period. Apply 15 kg of urea per mu as tillering fertilizer. When rice is in full flowering, apply 5-10 kg of urea per mu, 3 kg of potassium sulfate, and 20 kg of rice ternary compound fertilizer as flower-promoting and flower-preserving fertilizer. On the basis of applying organic fertilizer, chemical fertilizer application should focus on the early stage, with mid-layer fertilization as the main method. Strictly follow the fertilization principles of promoting at the front, controlling in the middle, supplementing later, and combining nitrogen, phosphorus, and potassium.
5. 30-35 days after transplanting, when the field tillers reach the designed effective panicles (generally 300,000-350,000 seedlings per mu), drain the water in a timely manner to sun the field and control ineffective tillering. After 5-7 days of sunning the field, irrigate promptly. Whether to sun the field, the degree of sunning, and the duration of sunning should also be determined in combination with climate, soil, fertilizer supply, and seedling growth. For fields with sufficient seedling number, deep leaf color, vigorous growth, and high fertility, sun earlier and more heavily, to the extent that a person standing does not sink in and the leaves clearly turn yellow; on the contrary, sun later, lightly, or expose the field, and it is sufficient that the field surface tightens slightly and the leaf color fades slightly. Sunning the field should not be excessive or insufficient, and should be flexibly controlled.
6. To ensure that irrigation does not cause the soil temperature to be too low and affect rice growth, warming irrigation should be carried out. When irrigating with river water, the irrigation time can be from 1-2 hours before sunset to 1-2 hours after sunrise; when irrigating with well water, first put the water into a sunning pond, extend the irrigation channel, widen the water inlet, and adopt methods such as surface water irrigation, striving to ensure that the irrigated water temperature is not too low and reducing the impact of low water temperature on rice tillering and growth and development.
7. Do a good job in pest and disease control during the rice growth period.
(1) Agricultural control: select disease- and pest-resistant varieties and adopt reasonable supporting cultivation measures (such as reasonable dense planting, fertilization, water management, etc.). (2) Physical control: use physical insect-killing lamps. (3) Chemical control: adopt mobile coordinated control methods. The main rice pests and diseases include bacterial leaf blight, rice blast, rice false smut, sheath blight, sheath blight leaf blight, stem borers, and planthoppers. For agent selection and dosage per mu: 100 g of 25% bismerthiazol, 30 g of 75% tricyclazole, 40 g of 20% validamycin wettable powder, 400 ml of 18% dimehypo aqueous solution, and 5 g of 70% imidacloprid, mixed with 60 kg of water for spray control.
The key technical points of rice field management are briefly introduced here, hoping to be helpful to everyone.