What are the agricultural meteorological elements and the relationship between agricultural production and meteorological conditions?

Agrometeorology is generally divided into four categories: l

What are the agricultural meteorological elements and the relationship between agricultural production and meteorological conditions?

Agrometeorology is generally divided into four categories: light, temperature, water and gas, in which light includes illuminance, light saturation point, light compensation point, sunshine hours and solar spectrum, temperature includes ground temperature, agricultural biological body temperature, water temperature, air temperature and accumulated temperature, water includes farmland water consumption, air temperature, precipitation, soil moisture and soil effective water content, and gas includes wind direction, wind speed and CO2.

1. What are the agrometeorological elements?

1, light

It mainly includes illuminance, light saturation point, light compensation point, sunshine hours and solar spectrum.

2. Temperature

It mainly includes water temperature, air temperature, ground temperature, agricultural biological body temperature and accumulated temperature.

3. Water

It mainly includes farmland water consumption, air temperature, precipitation, water surface evaporation, soil water content, soil effective water content, soil water potential, soil evaporation and transpiration.

Step 4 be angry

It mainly includes wind direction, wind speed, CO2 concentration (CO2 concentration), CO2 saturation point and CO2 compensation point.

5. Other elements

It mainly includes frost, dew, freezing and snow.

Second, the relationship between agricultural production and meteorological conditions.

1, light

(1) In agricultural production (the production activities of planting crops), it is usually necessary to have enough sunshine. With sunlight, crops can carry out photosynthesis through green leaves and continuously produce organic matter, thus providing some elements needed for crop growth and development.

(2) Because crops have different demands for sunlight, they can be divided into long-day crops and short-day crops according to their reflection on the length of sunlight. Common long-day crops are mainly wheat, and short-day crops are mainly rice.

(3) If short-day crops provide long sunshine, or short-day crops provide short sunshine, then crops may not grow well. Therefore, when planting crops in various places, it is necessary to choose suitable crop varieties according to the length of local sunshine time to ensure the normal growth and development of crops in the local area.

2. Temperature

(1) Generally speaking, the demand of crops for heat energy is expressed by temperature, and temperature is also one of the factors that affect the growth of crops. Too high or too low temperature may lead to poor crop growth and even death.

(2) Take eggplant as an example. Eggplant is a high temperature crop. The optimum temperature for seed germination is 25-30℃. After entering the seedling stage, the temperature is 25-30℃ during the day and 15-20℃ at night. When the temperature is lower than 15℃, the growth rate is slow and it is easy to cause flower drop.

3. Water

(1) In the process of crop growth, water is usually indispensable. If there is not enough water, crops can't grow normally. Besides irrigation, the water needed by crops also depends on rainfall.

(2) Insufficient rainfall will lead to drought, but too much rainfall will also lead to insufficient air in the soil for crops to breathe, and then crops will die due to lack of oxygen. Therefore, suitable water content is one of the conditions for the normal growth of crops.

(3) At the same time, air humidity also affects the growth of crops. Proper air humidity can generally make crops grow normally, but if the air humidity is too high, it will create favorable conditions for the occurrence and development of diseases, because most diseases occur in the environment with relatively high air humidity.

Step 4 be angry

(1) Wind can not only spread pollen to cereal crops, but also regulate the temperature and humidity between trees. However, if the wind is too strong, it will cause mechanical damage to crops and even lodging, thus affecting the yield of crops.

(2) At the same time, the concentration of carbon dioxide will also affect the growth of crops. With sufficient light, water and fertilizer, the yield of crops will generally increase with the increase of carbon dioxide concentration. However, if the concentration of carbon dioxide is too high, the stomatal conductance of leaves (the degree of stomatal opening) will decrease, the transpiration of crops will decrease, and then the internal temperature of crops will increase.

(3) When the temperature, carbon and nitrogen values in an object increase, it is easy to accelerate the senescence of crops. For example, if this happens in the growing period of crops, the reproductive growth period of crops will be shortened (that is, premature senescence of plants), which will usually affect the yield and quality of crops to varying degrees.

5. Frost and snow

(1) frost

(1) In early autumn and late spring, the temperature will drop sharply due to the invasion of cold air. If the temperature drops below the minimum temperature required for crop growth in a short time, crops will suffer from freezing injury, which is generally called frost.

(2) After frost occurs, various crops are usually affected to varying degrees. Take corn as an example. When the temperature drops to 0℃, corn usually suffers from mild frost, and the leaves will be hurt first. After freezing, the leaves will turn yellow, which will affect the photosynthesis ability of crops. When photosynthesis is affected, the output of nutrients will decrease. Because of the reduction of nutrients, the speed of corn filling will be reduced.

(3) At this time, if the temperature continues to drop to -3℃, there will be severe frost. In addition to a large number of leaves, the panicle neck usually dies from freezing, cutting off the channel of transporting nutrients from the stem to the grain, which leads to the forced stop of filling and further reduction of production.

(2) Snow

① Proper amount of snow usually has the function of heat preservation, which can reduce the loss of soil heat, prevent cold air from entering the snow-covered soil, ensure the overwintering crops and avoid freezing injury.

(2) However, if the thickness of snow is not enough, or there is alternate freezing and thawing weather after snowfall, crops will be uprooted and killed. It should be noted that uprooting means that crops will be exposed due to soil freezing and thawing, which sometimes leads to crop death.