Guidelines for agricultural disaster prevention released in April, floods in the south and drought in the north may occur.

In March, the impact of agrometeorological disasters was generally mild, and the main disaster was lack of rain in the middle and lower reaches of the Yangtze River. In April, we should focus on the adverse effects of drought in northern China on the growth and development of winter wheat, spring ploughing and spring sowing, continuous rain, waterlogging and diseases and insect pests on rape yield in the middle and lower reaches of the Yangtze River.

The agrometeorological disasters in March are cloudy and rainy in the middle and lower reaches of the Yangtze River, local gale, hail disaster and local drought in the northern winter wheat region.

There is little rain in the middle and lower reaches of the Yangtze River. From the end of February to the middle of March, the middle and lower reaches of the Yangtze River remained cloudy and rainy, with sunshine less than 40%. Among them, most of the rainy days in the south of the Yangtze River reached 15 to 29 days, more than 50% of the precipitation, and mild to moderate wet waterlogging occurred in low-lying fields in Jiangxi and southern Anhui, affecting the transformation of seedling conditions of summer grain and oil crops and bolting and flowering of rape. As a result, the occurrence of Sclerotinia sclerotiorum was earlier and more serious than that in perennial years and last year, and the rate of leaf disease in Jiangxi and Hunan increased by 31.2% and 16.9% compared with last year. According to the comprehensive analysis of the intensity of overcast and rain and the number of stations, the lack of sunshine in the middle and lower reaches of the Yangtze River is more serious than that in the same period last year, but lighter than that in normal years.

In April, summer grain and oil crops have entered a critical period of yield formation, water demand is relatively large, and spring sowing across the country will be carried out on a large scale. In April, we should focus on preventing the adverse effects of drought and late frost in the north, continuous rain and wet waterlogging in the south on the yield formation of summer crops, flowering of fruit trees and spring sowing.

First, attention should be paid to drought prevention in the western regions of North China, Huang-Huai and Northeast China. It is expected that in April, the temperature in the wheat region of North China and Huang-Huai is on the high side, there are many strong winds in spring, and the loss of soil moisture is accelerated. In addition, drought has been revealed in some areas, so it is necessary to timely irrigate wheat jointing and booting water to prevent the effects of drought; the western part of Northeast China should be prepared for sowing soil moisture.

Second, the middle and lower reaches of the Yangtze River should pay attention to the prevention of continuous rain and wet waterlogging. It is expected that in April, the precipitation in Jianghuai, central and eastern Jianghan and the northern part of Jiangnan will be more than 20%. It is necessary to guard against periodic lack of rain and wet waterlogging, and timely drainage and waterlogging after rainfall, so as to avoid premature senescence of rape and winter wheat roots, lodging in later stage and obstruction of spring sowing.

Third, the north should pay attention to guard against strong winds, sand and dust and late frost. April is the most frequent period of windy and dusty weather in the north, so it is necessary to reinforce the agricultural shed in order to avoid damage to the facility and freezing of vegetables in the shed. Before the cold air comes, measures such as mulching should be taken to prevent the frost injury of fruit trees during flowering. Spring sowing and cotton field plastic film mulching operations should avoid strong wind and dust weather to prevent losses.

Fourth, the summer harvest grain and oil producing areas should do a good job in the monitoring and prevention of diseases and insect pests. In the northern winter wheat areas, we should focus on preventing wheat aphids and the occurrence and development of wheat scab and Sclerotinia sclerotiorum in the middle and lower reaches of the Yangtze River.