Technical Guidelines for Post-Typhoon Lekima Recovery for Rice, Soybean and Corn Growers

Recently, due to the impact of Typhoon “Lekima”, rainfall in Northeast China has brought severe damage to crops. In response, the expert steering group of the Ministry of Agriculture and Rural Affairs, together with the National Agricultural Technology Extension and Service Center, has put forward technical guidelines for production to combat waterlogging and prevent low-temperature damage. Taking rice, corn and soybean as examples, let's see how to stop losses in time and reduce the damage!

I. Rice

1. Drain waterlogging and reduce waterlogging damage to promote early maturity

Flooded rice fields should be drained of standing water as soon as possible to prevent prolonged waterlogging from causing stem and leaf rot and root rot, and to reduce the impact of waterlogging on rice growth. At the same time, strengthen water and fertilizer regulation to ensure that the sensitive period of reproductive growth avoids low temperatures as much as possible and to reduce the rate of empty grains. Depending on the situation, spray potassium dihydrogen phosphate or early-maturity promoters on the leaves from the full heading stage to the mid-filling stage to accelerate grain filling, improve resistance to low temperatures and grain plumpness, and promote safe maturity of rice.

2. Prevent early frost

Keep timely track of temperature changes and real-time frost monitoring, and make preparations in terms of materials and techniques in advance. When light frost occurs in mid-September, irrigate once with shallow water to reduce the damage; once early frost occurs, quickly carry out artificial smoke fumigation to prevent frost, reduce the adverse effects of early frost, and at the same time appropriately extend the post-ripening growth period of rice to increase yield and quality.

3. Prevent lodging

In places where the practice of applying grain fertilizer exists, nitrogen fertilizer should be applied sparingly or reduced and potassium fertilizer increased according to rice growth conditions, to enhance the lodging resistance of the plants. For rice that has already lodged, those lodged at the base should not be propped up; a wooden stick can be used to separate the leaves of the panicles touching the ground from the soil surface, and then water can be used to wash away the soil to prevent panicle rot; those leaning at an angle with panicles touching the ground should be propped up, while those with neither panicles nor leaves touching the ground need no measures.

4. Prevent pests and diseases

Strengthen monitoring and early warning of pests and diseases, and seize sunny weather for pesticide spraying. At the late booting stage and full heading stage of rice, focus on controlling rice neck blast; 15 days after heading, control rice grain blast and branch blast, creating conditions for robust rice growth.

II. Corn

1. Drain waterlogging and reduce waterlogging damage to promote recovery

Corn fields with standing water should be drained as soon as possible to reduce field humidity, and topdressing should be carried out in time. For lodged corn, especially prostrate corn, straighten it in time, earth up 7—8 cm at the base and firm the soil. In fields where stalks are severely broken, the broken plants should be removed from the field as soon as possible to prevent rot from affecting the growth of normal plants, and at the same time, other crops with a shorter growth period should be replanted according to local conditions.

2. Regulate fertilizer and water to promote early maturity

For corn with delayed growth and development, spray quick-acting fertilizer at the right time and in the right amount, or appropriately apply a small amount of phosphorus and potassium fertilizer to enhance plant stress resistance. In the late filling stage of corn, spray potassium dihydrogen phosphate and growth regulators with early-maturity-promoting effects to accelerate corn filling, increase the seed-setting rate, and promote safe maturity of corn.

3. Prevent cold damage

Strengthen contact with meteorological departments, keep timely track of temperature changes and real-time frost monitoring, and issue early frost warning information in a timely manner. Where conditions permit, corn fields can be irrigated 2 days before frost occurs to increase soil moisture, raise ground temperature, and reduce the harm of low-temperature frost; once early frost occurs, quickly carry out artificial smoke fumigation to prevent frost, reduce the adverse effects of early frost, and at the same time appropriately extend the post-ripening growth period to improve corn yield and quality.

4. Prevent pests and diseases

Seize sunny weather for pesticide spraying, focusing on controlling pests and diseases such as the Asian corn borer, armyworm and northern corn leaf blight. Give play to the role of specialized pest and disease prevention and control teams, use machinery (drones) to carry out centralized spraying operations, and implement unified prevention and control to improve the effectiveness of pest and disease control.

III. Soybean

1. Fertilizer and water management to promote early maturity

For soybean fields in low-lying, waterlogging-prone areas where large areas of standing water have appeared, dredge ditches and dig seepage ditches in time to accelerate drainage and soil drying. Where conditions permit, aerial application and other methods can be used to spray potassium dihydrogen phosphate plus rice vinegar or trace fertilizers such as boron and molybdenum at the soybean seed-filling stage, to accelerate dry matter accumulation in the seeds and promote early maturity and increase grain weight.

2. Pest and disease prevention and control to reduce losses

Closely monitor field pests and diseases, do a good job of forecasting and prediction, and take timely chemical control measures. Focus on controlling soybean frogeye leaf spot, downy mildew, sclerotinia stem rot and soybean pod borer and other pests and diseases. In addition, remove weeds in time, and manually pull out large weeds before grass seeds form, to facilitate ventilation and light penetration, promote maturity and increase yield.

3. Artificial smoke fumigation to prevent early frost

Pay real-time attention to weather changes. At 2—3 a.m., when the temperature drops to the critical temperature for crop damage of 1—2℃, adopt the method of artificial smoke fumigation to prevent early frost. At the upwind edge of immature soybean plots, place straw, leaves, weeds and other materials and ignite them, burning slowly to cover the ground with a layer of smoke, raise the near-ground temperature by 1—2℃, change the local environment, and reduce frost damage. In addition, burning chemical substances such as red phosphorus in the field to form a smoke screen also has a frost-prevention effect.