What is the significance of meteorology to agricultural production?

1. Types and characteristics of meteorological disasters Meteorological disasters refer to disasters caused by rainstorm, blizzard, drought, lightning, hail, fog, strong wind, low temperature, high temperature, frost, freezing and cold wave. Jiangxi's climate is complex and changeable, especially in recent years, due to climate change and other reasons, all kinds of disastrous weather frequently appear, which has the characteristics of many types, wide influence and heavy harm. The main meteorological disasters are drought, flood, strong wind, hail, frost, cold wave, continuous rain, rain (fog), thunderstorm, etc., and disasters may occur all year round. 2. The impact of major meteorological disasters on agricultural production and preventive measures Among all kinds of meteorological disasters, drought and waterlogging have the greatest impact on agriculture, which not only occur frequently, but even accompany them, causing the greatest harm. Followed by low temperature, frost and continuous rain. It also has a certain impact on agricultural production, but the frequency is low and the harm is relatively light. 2. 1 drought. It refers to a meteorological disaster in which there is no rain or little rain for a long time on a sunny day, and the precipitation is obviously less than that in the same period of the year. In the national standard of meteorological drought grade, drought is divided into five grades, and the effects of different grades of drought on agriculture and ecological environment are evaluated: ① normal or wet waterlogging, characterized by normal or more precipitation than normal, and the surface is wet without drought; (2) Mild drought, characterized by less precipitation than normal, dry ground air, slight water shortage in soil, and slight impact on crops; ③ Moderate drought, characterized by less precipitation than normal, dry soil surface, insufficient soil moisture and wilting leaves of surface plants during the day, which has a certain impact on crops and ecological environment; (4) Severe drought, characterized by persistent and serious water shortage in soil, thick dry soil layer, wilting plants, withered leaves and falling off fruits, which has a serious impact on crops and ecological environment, and has a certain impact on industrial production and drinking water for people and livestock; ⑤ Extreme drought, characterized by long-term serious shortage of soil moisture, dry-up and death of surface plants, has a serious impact on crops and ecological environment, and has a greater impact on industrial production and drinking water for people and livestock. Drought is one of the most important natural disasters, and it happens to varying degrees almost every year. The main defensive measures against drought are as follows: ① adjusting crop layout according to the distribution of dry areas and planting drought-tolerant crop varieties; (2) Adopt irrigation and drip irrigation technology to save water; ③ Planting trees to improve the ecological environment; Fourth, strengthen the construction of farmland water conservancy infrastructure; The fifth is to develop air water resources, seize favorable weather conditions and carry out artificial precipitation enhancement. 2.2 rainstorm. Refers to the precipitation of more than 50 mm in 24 hours. According to its intensity, it is divided into three levels, and the 24-hour precipitation of 50.0~99.9mm is "rainstorm"; 100.0~249.9mm is "rainstorm"; More than 250mm is a "rainstorm". Heavy rain is easy to cause rivers to flood, flood grain fields, induce geological disasters such as mudslides and landslides, and directly threaten people's lives and property. The main defensive measures for rainstorm: First, timely listen to and watch the meteorological disaster warning information released by the meteorological department, reinforce dikes, dredge rivers, and inspect and maintain farmland water conservancy infrastructure; Second, timely organize harvesting or eliminate stagnant water in the field to prevent waterlogging from flooding crops; The third is to maintain houses and farmhouses to prevent houses or walls from collapsing due to heavy rain; The fourth is to avoid dangerous areas prone to flash floods, mudslides and landslides. 2.3 Hail. Refers to the solid precipitation falling from cumulonimbus clouds, generally spherical, alternating with transparent and translucent ice layers. Hail is often accompanied by storms, lightning and thunder. Hail can easily hurt people and animals, destroy crops, and cause crop yield reduction or even crop failure. The main defensive measures of hail: first, harvest mature crops in time; Second, in hail-prone areas, planting trees, increasing the green area, improving the geomorphic environment and destroying the conditions for the formation of hail clouds; Third, in the rainy season, farmers should carry hail suppression tools with them when working in the fields, and meteorological departments should carry out artificial hail suppression operations in time to reduce disaster losses. 2.4 strong wind. Winds with wind speed ≥ 17m/s and wind force ≥8 are called strong winds, which are usually divided into three types: northern cold air southbound gale, thunderstorm gale and typhoon hurricane gale, and the northern cold air southwards gale is the most. Strong winds can not only destroy farmhouses, crops, trees and communication facilities, but also cause sand and stones to fly and harm people and animals. The main defensive measures of strong wind: first, reinforce vegetable greenhouses and fruit trees in time; second, cut off outdoor dangerous power supply; The third is to reduce outdoor activities and try not to work in the fields. 2.5 It rains continuously. It refers to the weather process in which there is precipitation for more than 5 consecutive days, the cumulative precipitation is more than or equal to 30mm, the rainy days are continuous, the rain is heavy, the humidity is high, and the light is low, which is not conducive to the growth and development of crops and the harvest of mature crops. Continuous rainy days have a great influence on the quality of vegetables, cotton, soybeans and peanuts. Continuous rainy days during sowing delayed sowing and led to crop failure and yield reduction. The main defensive measures for continuous rainy days: first, according to the weather forecast, do a good job of grabbing grain and catching the sun in time; At the same time, do a good job of moistureproof to prevent mildew; Second, do a good job of ditch cleaning and drainage in continuous rainy days to prevent waterlogging; Third, when spraying pesticides on crops, add adhesives to the liquid medicine, such as adding proper amount of vegetable oil, soybean powder and starch to the liquid medicine to ensure the pesticide application effect. 2.6 Tidal cold. This is a serious disastrous weather process. Due to the invasion of cold air, the temperature dropped by more than 8℃ within 24 hours, and the lowest temperature on that day was below 4℃. Or 48 hours cooling 65438 00℃, the lowest temperature is lower than 4℃, known as the cold wave. When the cold wave crosses the border, it is often accompanied by northerly winds of 6~8, which makes the temperature drop suddenly along the way, which is easy to cause freezing damage and harm to agriculture and animal husbandry. The main defensive measures of cold wave: first, before the cold wave comes, crops that have been watered for the winter should be hoed, loosened and ventilated; Second, when the cold wave comes, the temperature in the greenhouse drops, which slows down the growth of crops in the greenhouse, so the supply of fertilizer and water should be increased; The third is to strengthen the shed to prevent it from being pulled off by the strong wind. 2.7 low temperature frostbite. It refers to a weather phenomenon that the temperature in a certain period of time and a certain area is obviously low, which affects the normal growth and development of crops. It can be divided into four types: cold injury, cold injury, freezing injury and freezing injury. The freezing injury of crops is caused by the fact that the ecological conditions of overwintering exceed the cold resistance. The degree of freezing injury mainly depends on the intensity and duration of cooling, but it also has a great relationship with varieties, sowing date, sowing amount, soil, farming quality and water and fertilizer management. Therefore, even if crops adapt to the ecological conditions of overwintering, they should also be prevented from freezing injury. The following measures can be taken to prevent freezing injury: first, cultivate and select cold-resistant varieties, do a good job in the rational distribution of varieties, and arrange the sowing date and sowing amount reasonably according to the vernalization characteristics of varieties; The second is to improve the quality of soil preparation and sowing, and cultivate strong seedlings to survive the winter; Thirdly, irrigation, intertillage, soil conservation and anti-freezing can be adopted; Fourth, increase the application of phosphorus and potassium fertilizer to cover the winter. 3. Countermeasures for Meteorological Disasters 3. 1 Meteorological Disaster Prevention is the abbreviation of meteorological disaster prevention and mitigation activities, and it is the summary of meteorological disaster monitoring, forecasting, early warning, investigation, evaluation and disaster prevention and mitigation activities. Meteorological disaster prevention is a very complicated social system engineering. We should not only do a good job in preventing the possible impact of meteorological disasters on agriculture, transportation and people's lives and property, but also do a good job in emergency rescue after meteorological disasters occur. There are many departments involved in meteorological disaster prevention. Only under the unified leadership and coordination of the government, the defense responsibilities of relevant departments are clearly defined and the organic linkage between departments is promoted, can the overall defense of meteorological disasters be truly realized. 3.2 Strengthen the infrastructure construction of meteorological disaster prevention and mitigation, and enhance the ability of meteorological disaster prevention and mitigation. Relying on the modern numerical weather forecasting system, professional forecasting systems such as short-term weather forecasting and early warning, short-term and medium-term forecasting, short-term climate forecasting, agrometeorology, hydrometeorology and geological disasters have been initially established. The early warning level of short-term approaching forecast and the accuracy of short-term forecast have been steadily improved, and the early warning level of strong convection, rainstorm and drought has made great progress. The meteorological grades of geological disasters, pests and diseases, fires, electricity and traffic, and the impact assessment of climate change on agriculture and water resources jointly produced and released by various departments have played an important role in avoiding or reducing the losses caused by meteorological disasters. 3.3 Take demand as the traction, and actively innovate the modern agrometeorological service system. Vigorously implement the cloud water development project in the air and build a standardized hail suppression and precipitation enhancement base to provide guarantee for drought relief, alleviate water shortage and protect the ecological environment. Strengthen the construction of rural meteorological disaster prevention system, establish a team of township meteorological information personnel, and do a good job in meteorological services for agriculture, rural areas and farmers.