I make a popular science video and all the emperors learn from it!

[Popular science on the earth, the ten most precious natural resources!]

[Third place: soil resources.] 】

[Soil resources refer to the general term of soil types with agricultural, forestry and animal husbandry production properties. 】

Soil is an important part of the entire terrestrial ecosystem on the earth, and it is the most basic natural resource that human beings rely on for survival and can be constantly renewed. 】

[If properly developed and utilized, soil resources can be continuously renewed, which can ensure the growing needs of human production and life. 】

【Category:】

[Soil is divided into: Soil can be divided into three categories: sandy soil, clay soil, and loam. 】

[The nature of sandy soil: high sand content, coarse particles, fast water seepage, poor water retention performance, good aeration performance. 】

[The properties of clay soil: low sand content, fine particles, slow water seepage, good water retention performance, poor aeration ~. 】

[The nature of loam: sand content is average, particles are average, water seepage rate is average, water retention performance is average, aeration performance - general. 】

【......】

【Characteristics of soil resources:】

[1. There are many types of soil, extremely rich resources, and huge production potential. 】

[Due to the vast area and complex natural conditions, the soil resources are extremely rich. 】

There are 13 soil classes and 78 soil types from the gray soil in the cold temperate zone to the brick red soil in the tropics, from the salt soil of the coastal plain to the alpine meadow soil of the Qinghai-Tibet Plateau, from the loess soil of the Loess Plateau to the paddy soil in the south. 】

【...】

[2. Soil resources in mountainous areas account for a large proportion. 】

[China is a mountainous country, and the soil of various mountains, hills and alpine accounts for about 65% of the total land area of the country, and the flat soil accounts for only 35%. 】

[Compared with plains, mountains have certain restrictions on the development of agricultural production, and improper use can easily cause soil erosion and resource destruction. However, the mountainous area is rich in resources and is suitable for the development of diversified operations. 】

[3. The regional distribution of soil resources is unbalanced. 】

Although the eastern monsoon region accounts for 47.6% of the country's total land area, it concentrates about 90% of the country's cultivated land and forest land and 95% of the agricultural population. 】

[The arid area of Mongolia and Singapore accounts for 29.8% of the total land area of the country, but only accounts for about 10% of the country's cultivated land. 4.5% of the agricultural population. Due to drought and lack of rainfall, lack of water sources, and the large area of the desert Gobi, which is difficult to use, the hazards of sandstorms and salinity are widespread and serious. 】

[The Qinghai-Tibet Plateau accounts for 22.6% of the country's total land area, and the proportion of the population is 0.5%, but due to the lack of heat, the frost-free period is short. Most of them are currently difficult to use. 】

【...】

[4. The per capita cultivated land area is small, and the soil resources of suitable agricultural wasteland are not much. 】

[China's cultivated land per capita is 0.1 hectares, only 29.2% of the world average, and forest land per capita is 0.11 hectares, accounting for 1/9 of the world's per capita number. Natural grassland is slightly more abundant, 0.29 hectares per capita, but still less than 1/2 of the world's per capita. 】

[This characteristic is a restrictive condition affecting the development of agricultural production in China, and most of the wasteland suitable for reclamation in China has generally been developed and utilized. 】

【...】

[5. There is a low-yield soil that accounts for about 1/3 of the existing cultivated land. 】

[China has a long history of soil resource development, on the whole, the degree of development and utilization is relatively high, accounting for about 7% of the world's arable land to support nearly 1/5 of the world's population. 】

【...】

【Some of the most fertile lands in the world:】

[Black soil is the most fertile soil in the world, and there is a metaphor of "one or two soils and two oils". 】

[It is characterized by pure black, which can only be formed in the cold temperate zone where it is warm and humid in summer and cold and dry in winter, so it is also known as cold black soil and is also known as leaching black soil because of its formation. 】

[There are only three black soil areas in the world, and one red black soil area. 】

[Black soil area: They are the Wukelan Plain, the Mississippi Plain of the United States, and the Northeast Plain of China. 】

[Reddened black soil area: South America a Gentinglian to Wugui, Pampas. 】

【...】

[Soil Pollution Problem:]

[All substances that hinder the normal function of soil, reduce crop yield and quality, and indirectly affect human health through grains, vegetables, fruits, etc., are called soil pollutants. 】

[When the soil contains too many harmful substances, exceeding the self-purification capacity of the soil, it will cause changes in the composition, structure and function of the soil, microbial activities are inhibited, and harmful substances or their decomposition products gradually accumulate in the soil, and are indirectly absorbed by the human body through "soil-plant-human body", or through "soil-water-human body", to the extent of endangering human health, which is soil pollution. 】

[Factors of soil pollution: Due to the rapid growth of population and the rapid development of industry, solid waste is constantly piled up and dumped on the soil surface, harmful wastewater continues to penetrate into the soil, and harmful gases and dust in the atmosphere continue to fall into the soil with rainwater, resulting in soil pollution. 】

[There are many sources and types of soil pollutants...]

【...】

[Hazards of Soil Pollution:]

[1. Soil pollution leads to serious direct economic losses - pollution of crops and reduced yields. (Read the violent novel, go to the Feilu Novel Network!)

[There is a lack of systematic investigation data on the economic losses caused by various soil pollution.] Taking soil heavy metal pollution as an example, the country's annual grain production is reduced by more than 10 million tons due to heavy metal pollution, and the grain polluted by heavy metals is as much as 12 million tons per year, with a total economic loss of at least 20 billion yuan. 】

[2. Soil pollution leads to a continuous decline in biological quality. 】

[Most of the soil in the suburbs of cities in China has been polluted to varying degrees, and the content of heavy metals such as cadmium, chromium, arsenic, and lead in grain, vegetables, fruits and other foods in many places exceeds the standard and is close to the critical value. 】

In addition to affecting the hygienic quality of food, soil pollution also significantly affects other qualities of crops. 】

[In some areas, the polluted irrigation has made the taste of vegetables deteriorate, easy to rot, and even have an unpleasant odor; the storage quality and processing quality of agricultural products cannot meet the requirements of deep processing. 】

[3. Soil pollution endangers human health. 】

[Soil pollution will cause pollutants to accumulate in plants (crops) and enrich into human and animal bodies through the food chain, endangering human and animal health, causing cancer and other diseases. 】

[4. Soil pollution leads to other environmental problems. 】

[After the land is polluted, the polluted topsoil with high concentrations of heavy metals is easy to enter the atmosphere and water bodies under the action of wind and water respectively, resulting in air pollution, surface water pollution, groundwater pollution and ecosystem degradation and other secondary ecological and environmental problems. 】

【......】

After reading it, the ancients were surprised and a little incomprehensible at the same time.

"Wow! The third place is the guy who eats for our people!"

"That's not right, why is the land only ranked third, what are the top two..."

"Day! This time it's always on the line, there is a large piece of the best black soil, but it is per capita, I really can't bear it!"

"The minister wants to carry the coffin and die! Please play Your Majesty, let Your Majesty take the other three good pieces of land, all over!"

"It's uncomfortable, good land, it's so rare, how can it be polluted. "

"It's so angry, it's all done by future generations!"

"That's right! Only after a few years of eating will the next generation start to smash the rice bowl!"

“..."

[Popular science continues.] 】

[In order to cope with the increasing problem of land pollution, a new technology has emerged in recent years. 】

【Soilless cultivation!】.