The relationship between soil, plant nutrition, and human health

Soil is derived from the weathering of mineral rocks (parent rocks) (as shown in Figure 1). 95% of soil solids are minerals, and only a small portion (about 2%) undergoes activation during the soil-forming process, becoming effective nutrients for plants and constituting an important part of soil's natural nutrients.

There are more than 70 chemical elements found in plant bodies, among which 11 elements such as carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, sodium, sulfur, and silicon account for 99.95% of the active matrix of the plant body. The content of the remaining 60 elements (such as essential elements such as iron, manganese, copper, zinc, boron, molybdenum, chlorine; beneficial elements such as silicon, nickel, cobalt, selenium, sodium, vanadium, and rare earth elements; toxic elements such as chromium, cadmium, lead, arsenic, mercury, aluminum and other heavy metals) is very small, accounting for only 0.05% in total.
As Nobel laureates Carrel and Pauling have said, "Minerals in the soil control the metabolism of plants, animals, and humans. The fertility of the soil determines the health of all life." "Every disease and ailment of humanity can be traced back to a lack of minerals." The report "The State of the World's Children 2019: Children, Food, and Nutrition" recently released by UNICEF shows that half of the world's children suffer from "hidden hunger.
1、 The relationship between soil and plant nutrition
There are as many as 73 types of minerals and trace elements that can be found in soil, including essential elements for plant growth (Figure 2), beneficial elements (silicon, nickel, etc.), and toxic elements (mercury, lead). Some experts have published articles suggesting that nickel, silicon, cobalt, sodium, and other essential nutrients are also needed by plants. Some lower plants also require vanadium, gallium, germanium, and tungsten, but it has not been proven that all plants require them.

(1) Tungsten (W) is toxic to nitrogen fixing organisms, mainly manifested in interfering with the metabolism of molybdenum and inhibiting the activity of molybdenum enzymes such as nitrogenase and tetrathiosulfate reductase in the organism, as it competitively inhibits the absorption of molybdenum;
(2) Aluminum (Al) inhibits the absorption of iron and calcium, interferes with phosphorus metabolism, and hinders the absorption and transportation of phosphorus to the aboveground parts; The toxic symptoms of excessive aluminum include inhibition of crop root growth, thickening of root tips and lateral roots to brown, obstruction of aboveground growth, dark green leaves, and purple stems;
(3) Selenium (Se) is highly enriched in selenium loving plants, and a lack of Se prevents normal growth and development;
(4) Chromium (Cr) is an essential trace element for humans and animals. Chromium participates in a series of cell components. Chromium deficiency in the body can cause atherosclerosis; Chromium can increase the activity of enzymes in plants, increase the content of chlorophyll, organic acids, glucose, and fructose, accelerate plant growth, enhance plant resistance to diseases, and increase crop yield. But if it contains too much chromium, it is harmful to both humans and animals and plants.
(5) Experiments have shown that trace amounts of arsenic (As) compounds have a stimulating effect on the growth of certain plants and can improve the quality of certain crops. The famous product "Baisha Citrus" from Baisha, Changning County, Hunan Province, has a bright color, fragrant aroma, and a delicious sour and sweet taste; The ginger produced in Xiling, Changning County has tender flesh, little fiber, and a special aroma. According to analysis, these are all related to the arsenic content in the soil.
Therefore, whether mineral elements are beneficial or harmful, and whether life needs them or not, are all relative. Elements that are currently considered unnecessary or toxic to life may be discovered in the future to be beneficial or necessary for life. The effect of any element on plants depends not only on its chemical properties, but also on whether its "appropriate quantity" and "reasonable proportion" with other elements are suitable for the balanced needs or tolerance of the plant at different growth stages (Figure 3).

Figure 3
2、 The relationship between soil and human health
Research has shown that trace elements in the human body are positively correlated with the abundance of crustal elements, which is a result of the transmission of the soil plant animal human food chain. People have discovered that there are over 60 chemical elements in human blood, which have a clear correlation with the distribution of the same chemical elements in the Earth's crust (Figure 4).

Figure 4
If the concentration of chemical elements in the crust of a certain region exceeds the normal range of changes that the human body is adapted to, it may cause pathological changes.
Example 1: Iodine deficiency disease (IDD) caused by iodine deficiency has been found to be a pathogenic factor for goiter and cretinism in the Chinese population.
Example 2: In the 1970s, more than 300 counties in 10 provinces of China were affected by Keshan disease, forming a narrow and elongated outbreak zone from northeast to southwest. In the prevention and treatment of Keshan disease, it was first discovered that selenium deficiency is an important cause of Keshan disease.
Example 3: In the 1980s, fertilizers containing rare earth elements typically achieved a yield increase rate of over 20%. However, 30 years later, it was discovered that long-term low-dose intake of rare earth elements in the human body may affect brain function, increase liver and kidney burden, lead to changes in liver tissue, and affect female fertility; Agricultural rare earths at doses higher than 2mg/kg can cause DNA damage to liver cells and red blood cells through the placental barrier.
In short, during this long process of occurrence and evolution (Figure 5), plants, animals, and humans have all formed a close dependence on the mineral element background of the crustal lithosphere. Although people's understanding of trace elements is still very new, researchers are still discovering more important aspects of them every day. For example, in order for the body to absorb calcium, it must have the trace element boron. If you cannot obtain enough boron from your diet, your body cannot absorb calcium from food, drinking water, or supplements. For example, the dinosaurs that dominated the Earth's surface during the Jurassic period suddenly became extinct due to an excessive amount of iridium caused by an extraterrestrial asteroid colliding with the Earth. And a small number of biological species adapted to high concentrations of iridium survived and evolved into the current population of organisms on Earth.

Figure 5
3、 Conclusion
The relationship chain between soil, plant nutrition, and human health should be considered as a systemic issue, and the problem should be solved through a "positive and negative" dual path. As researcher Yin Xuebin said, "To enable beneficial nutrients to enter the human body and exert their effects, it is necessary to conduct forward research on the transmission process of beneficial substances from rocks to the human body, find the laws of substance flow transmission, and reverse design based on the actual needs of the human body for functional components
The basic research on soil plant nutrition human health has attracted the attention of geophysicists, physiologists, soil scientists, agricultural chemists (fertilizers), and agronomists, as well as experts in animal husbandry, medicine, hygiene, nutrition, and environmental science. They have conducted research on key scientific issues related to rock soil fertilizer crop/animal food human body, material flow transmission laws and regulation technologies, and are forging ahead to come up with a "Chinese solution" to address the problem of "hidden hunger" as soon as possible.