How to do when corn seedlings suffer from waterlogging? What are the countermeasures?

Although corn water demand is very large, but it is not tolerant of waterlogging. Waterlogging will make corn grow slowly, plant weak, leaves yellow, stems red, roots black and rotten, seriously affecting corn growth and yield. So what if corn seedlings suffer from waterlogging? What are the countermeasures?

I. Response measures for corn suffering from waterlogging

1. Rapid drainage and stain reduction

After rainstorm, according to the ponding situation and terrain, drainage machinery and drainage ditch shall be adopted to drain the ponding water in the field and stagnant water in the cultivated layer as soon as possible, reduce the ponding time in the field, dredge and dredge the ditches in the field to ensure smooth drainage of the ditches in the field. At the same time, the leaves and stems should be brushed off or washed to restore normal photosynthesis.

2. Early lodging

After the storm, the lodging corn should be lifted up as soon as possible. If lodging occurs before jointing, the corn itself has certain ability to recover upright, so it is unnecessary to straighten it manually. If lodging occurs after tasseling, it must be manually lifted up, but it should be lifted up as soon as possible, preferably within 2 to 3 days.

3. Timely supplement fertilizer and promote strength

A certain amount of quick-acting chemical fertilizer should be applied in time after the corn is flooded to promote the recovery of corn growth and promote the weak to turn strong.

4. Topdressing outside roots

After the accumulated water in the field is discharged, foliar fertilizer should be sprayed in time. 45 - 60kg of 0.2%-0.3% potassium dihydrogen phosphate +1% urea aqueous solution is sprayed on corn fields every 7 - 10 days for 2 - 3 times continuously.

5. Fertilizer supplementation

After the plant root absorption function is restored, the roots are fertilized to supplement soil nutrients. For corn plots before heading and flowering stage, 20~ 25kg high concentration compound fertilizer shall be applied per mu, and 7.5~ 10kg urea shall be applied per mu at large bell stage or heading and flowering stage to promote corn recovery and health.

6. Strengthen pest control

After the disaster, due to the high humidity in the field, diseases and insect pests often occur and spread. Therefore, for the affected plots, the prevention and control of pests such as corn borer and corn spot disease in the middle and late stages shall be emphasized.

II. Measures to prevent corn waterlogging

1. Selection of waterlogging resistant varieties

Generally, waterlogging resistant varieties have developed air cavities in their roots, and their leaves are better in color and less withered under waterlogging prone conditions. In waterlogging prone areas, corn hybrids can be selected from existing ones that are more resistant to flooding.

2. Selection of land

In flood-prone areas, try to choose high-lying plots for planting, rather than low-lying plots with heavy soil and high groundwater level.

3. Ridge cultivation

In low-lying areas prone to waterlogging, ditches and ridges are dug in farmland, and corn is planted on ridge platforms. Due to good ventilation conditions, waterlogging damage can be reduced and harm can be changed into benefit.

4. Adjust sowing date

Maize seedling stage is most afraid of waterlogging, and its waterlogging resistance ability gradually increases after jointing. Therefore, sowing date can be adjusted so that the most afraid of waterlogging growth stage with the rainy season easy to stagger. In North China, the rainy season usually begins in late June or early July. Interplanting wheat on ridges and sowing early after wheat harvest are adopted to make corn jointing before the rainy season and improve its stress resistance.

5. Drainage

A three-stage drainage system can be established, which combines the ridge ditch between corn rows, the main drainage ditch perpendicular to the rows, and the field drainage ditch parallel to the rows every 25 meters. The depth of the ditch is deeper than that of the first stage, so that the accumulated water in the field can be quickly drained. Border drainage is adopted in the south. Wide and shallow furrows are adopted in high terrain and good drainage plots; narrow and deep furrows are adopted in low-lying land. Straight furrows are required, drainage ditches are unobstructed, rain flows with rain, and rain stops water discharge.

6. Cultivation

When the land can be cultivated, it should be tilled in time to promote the recovery of corn growth.

7. Increase the application of quick-acting nitrogen fertilizer

The waterlogging of maize often shows yellow leaves, red stems and delayed seedling. It can be increased by applying available nitrogen fertilizer to change nitrogen nutrition of plants, restore their growth and reduce waterlogging losses.

8. Prevention and control of diseases and pests

After waterlogging, diseases and insect pests are often aggravated, especially in the Yellow River, Huai River and sea areas. It is necessary to focus on the prevention and control of corn borer. Diseases and insect pests should be predicted and prevented in time.

9, promote early maturity

After waterlogging occurs, maize growth period is often delayed and may suffer from the threat of low temperature and cold damage. To promote the ripening of grain filling, measures such as emasculation, leaf priming, root cutting and bract peeling after milk ripening should be taken. Chemical ripening agents sprayed on corn leaves can also have the same effect.

10. Autumn sowing of corn

If the southern region is seriously affected by waterlogging, autumn sowing of corn can be adopted as a disaster relief measure. Early maturity maize hybrids should be selected, and efforts should be made to plant them before the end of August, increase density, increase application of quick-acting fertilizers, control diseases and insect pests, and strive for better harvest.