What are the remedial measures after rice suffers from flooding?

Rice has strong waterlogging tolerance. After being submerged for about 3 days, about 80% of the rice seedlings can still survive, and it is enough to strengthen management. After being submerged for 4-7 days, 50%-80% of the rice seedlings survive, so it is necessary to promptly thin and replant seedlings to ensure a sufficient population. After being submerged for more than 7 days, only about 30% of the rice seedlings survive, so replanting or switching to other crops should be considered. It is necessary to adapt to local conditions, provide guidance by category, and carefully carry out post-disaster management of rice. As long as rice seedlings still have green leaves, the inside of the leaf sheath is still green and has a certain hardness, and the white roots or root system are light yellow, and after emerging from the water for 2-3 days, new central leaves can be seen emerging and new roots can be seen sprouting. When the main stem is peeled open for inspection, the growing point appears crystal bright, does not shrink, and is not cloudy, such rice seedlings can all survive. Within 3-5 days after draining the water, according to the growth and development progress and the number of surviving basic stems and tillers, keep the plants if possible, and reduce the area to be replanted as much as possible.

Drain the accumulated water in the field as soon as possible. It is necessary to seize the time, race against speed, adopt all necessary and possible means, and make an all-out effort to drain the accumulated water to reduce the harm of waterlogging. Quickly dredge the field ditch system, open drainage facilities, lower the peripheral water level, and ensure that the accumulated water in the field can be drained out. However, note that high temperatures may occur after rain, so the field water should not be completely drained; an appropriate water layer should be retained to avoid damaging the seedlings by high temperature.

Apply recovery fertilizer after the disaster as early as possible. After rice is submerged, fertilizer should be applied promptly to promote recovery growth after the disaster. The fertilizer type should mainly be quick-acting nitrogen fertilizer, together with phosphorus and potassium fertilizer. For fields with a short submergence time and light damage to rice seedlings, the fertilizer amount can be smaller. For some fields with a long submergence time and severe damage to rice seedlings, more should be applied appropriately, but it must be applied lightly multiple times to prevent applying too much fertilizer at one time and causing fertilizer damage to the seedlings. While applying recovery fertilizer, combine "foliar spraying and root topdressing" and spray high-efficiency foliar fertilizer to promote recovery growth.

Strengthen water and slurry management. After drainage, on the basis of the floating mud in the rice field having settled, adhere to alternating dry and wet conditions, and irrigate with fresh water intermittently, which both maintains soil aeration and meets the water needs of the rice seedlings.

Pay attention to pest and disease control. For direct-seeded rice fields that were sown late due to the impact of continuous rainfall, control of small brown planthopper should be strengthened. The leaves and tillers that emerge after submerged rice resumes growth are relatively tender and green, and are susceptible to damage from rice planthopper, rice leaf roller, yellow stem borer, sheath blight, bacterial leaf blight, and others. Recently, the Jianghuai and Huaibei regions should do a good job in controlling the second generation of small brown planthopper, especially in direct-seeded rice fields and late-transplanted fields.