Influence of waterlogging on Maize and Technical suggestions for Post-disaster Management

According to the news released by the provincial meteorological station, from 08:00 on July 18 to 14:00 on July 20, there was a weather process of rainfall in most parts of our province. The average rainfall in the rainfall area is 114mm. In Baoding, Langfang and most areas to the south, the rainfall is generally more than 100mm (rainstorm), of which 1170 townships have more than 100mm rainfall (heavy rainstorm). Especially in the southwest of Baoding, the west of Shijiazhuang, the west of Xingtai and the central and western part of Handan, there are 289 townships with rainfall more than 250mm (torrential rain). Among them, Cixian, Jingxing, Zanhuang, Yuanshi and Pingshan have a total of 9 stations with rainfall of more than 600 mm. Due to the relatively high intensity of the precipitation process, accompanied by strong winds, waterlogging or waterlogging occurred in some areas of corn fields, and some fields showed different degrees of lodging.

First, the harm of waterlogging to corn

In the land where waterlogging occurs, because the corn plants are soaked in water, the roots can be poisoned in a short period of time, resulting in partial root rot, and soaking for a long time leads to root asphyxiation and death. The waterlogged plots generally lead to the decrease of root activity, the weakening of the ability of plants to absorb water and nutrients, and the retardation of plant growth and development. When waterlogging occurs, because the soil is saturated and soft, it is easy to lodge if accompanied by strong wind at the same time. The resistance of maize to waterlogging is related to the growth period, and the bigger the plant is, the stronger the resistance to waterlogging is. At present, most of the spring sowing corn in our province has entered the male pollen stage, and the resistance to waterlogging is relatively strong, but the summer sowing corn is in the small trumpet stage, and the resistance to waterlogging is relatively weak.

II. Field management techniques after waterlogging

1. Eliminate stagnant water in the field. If there is obvious stagnant water in the field, we should do everything possible to eliminate the stagnant water in the field and reduce the soaking time of corn plants. To make full use of ditches, ground drains and other facilities, or manual excavation of drainage ditches, machines and pumps and other facilities can be used for drainage if possible. If there is a large amount of sludge on the leaves of the plant, it should be washed off in time when draining, so as to increase the light area of the leaves and promote its recovery to normal photosynthetic capacity.

two。 Ploughing and dispersing moisture. For the plots that have excluded stagnant water in the field or are only affected by waterlogging, ploughing and hoing can be carried out in time when the field can enter the field, which is beneficial to the dispersing of soil moisture, improving the rhizosphere environment and promoting the recovery of root growth. in addition, it can also break the soil consolidation that may be caused by rain. Be careful not to destroy the fresh roots when ploughing. For the plants with skew and lodging, the plants can be righted according to the situation, and the surrounding soil at the base can be compacted, which can not only prevent secondary lodging, but also promote the development of aerial roots of maize.

3. Replenish quick-acting fertilizer. The maize harmed by waterlogging is generally characterized by yellowing leaves and slow growth. After the disaster, we should lose no time to apply quick-acting fertilizer to promote the recovery of maize plant growth. In view of the fact that the summer corn in our province will enter the big trumpet mouth period, it is suggested to combine the big trumpet mouth period topdressing with post-disaster fertilizer management. The plots that have not yet applied panicle fertilizer can apply 20kg urea per mu, and the plots that have already applied panicle fertilizer can apply 5kg more urea per mu. Topdressing must be applied deeply in trenches or in combination with ploughing to avoid spreading. When it clears up after rain, use 0.5% urea + 0.2% potassium dihydrogen phosphate solution for foliar topdressing in time, and make sure that urea and potassium dihydrogen phosphate are completely dissolved and mixed when spraying, so as to avoid leaf burns caused by excessive local concentration and aggravate the degree of damage; generally, it can be sprayed twice in a row, with an interval of about 7 days.

4. Do a good job in the prevention and control of diseases and insect pests after the disaster. After the disaster, the plant growth and development is poor, and the ability to resist the harm of diseases and insect pests is reduced; in addition, due to the high humidity and high temperature in the field after waterlogging, it is very easy to induce the occurrence of diseases and insect pests. Summer corn should pay special attention to the prevention and control of diseases such as brown spot, root rot and top rot; the greater field humidity after rain is conducive to the hatching of corn borer, which is the key object of prevention and control of post-disaster pests. Spring corn should especially strengthen the prevention and control of diseases such as leaf spot and insect pests such as corn borer. Spring corn sown in early spring in summer sowing area should pay attention to the occurrence of bacterial wilt when it suddenly clears up after rain. In addition, in the case of too much Rain Water and too much soil moisture, it is easy to breed weeds in the field, and the control of weeds in the field should be strengthened after waterlogging.

Third, the management technology of lodging field.

If the lodging occurs at the same time in the waterlogged area, the corresponding field management measures can be taken according to the specific situation of the lodging.

1. Spring sowing corn or the plot that has entered the stage of male pollen dispersing, the lodging plants have basically lost the ability to restore upright growth by themselves, so they need to be artificially lifted after lodging and fixed with soil.

two。 At present, summer corn is in the stage of small trumpet mouth, after lodging, it generally does not need to take special management measures, and will slowly restore its upright growth after rain.

3. In the summer sowing plots washed down by the flood, the leaves of the plants are often partially buried in silt, making it difficult for the plants to restore upright growth by themselves. This kind of land should remove the soil from the leaves as soon as possible after the disaster, or cut off the leaves buried by the mud with a sickle to help the plants return to upright growth as soon as possible.

4. After lodging, the summer sown corn with some sediment in the heart leaves often leads to difficulties in the extraction of the heart leaves. After a disaster, this kind of land can use a sickle to cut off the heart leaves that have silted up and help to extract the subsequent leaves. But cut off as few leaves as possible, and try not to hurt the apical growth point of the plant.