The amount of heavy metals in the soil can lead to the death of plants

Different plants and different varieties of the same plant have very different tolerances and absorption capacity of heavy metals in the soil, and the migration ability of different heavy metals in the soil-plant system (i.e., the difficulty of being absorbed by plants in the soil) is also different, which makes it difficult to understand the heavy metal data itself, its transmission process in the ecological chain and food chain, and the interpretation of the impact on ecosystems and human health. The conversion of sampling points and areas under different precision sampling is also a challenging problem.

Characteristics of heavy metal pollution in soil.

1. Heavy metals cannot be degraded by microorganisms and are long-term and potential pollutants in the environment;

2. Due to the adsorption of soil colloids and particulate matter, it exists in the soil for a long time, and the concentration is mostly distributed vertically;

3. It reacts with ligands (chloride ions, sulfuric acid ions, hydroxide ions, corrosives, etc.) in the soil to form complexes or chelates, resulting in greater solubility and migration activity of heavy metals in the soil;

4. Soil heavy metals can be bioenriched through the food chain to produce biomagnification;

5. The forms of heavy metals are different, their activity and toxicity are different, and the conditions such as soil pH, EH, particulate matter and organic matter content profoundly affect its migration and transformation in the soil;

Resources.

The main hazards of heavy metal cadmium pollution to plants are ().

a.The plants are dwarfed.

b.There is only passive enrichment, no harm.

c.Destroy the chlorophyll of the leaves to form this good structure.

d.Slow growth.

Correct answer: ACD

Excessive levels of heavy metals in the soil can have a serious impact on plant growth and lead to seedling death. Here's a detailed explanation:

1. Lead (PB).

When the lead content in the soil is exceeded, it will hinder the absorption of iron in plants, resulting in poor plant growth, reduced pigment synthesis, stunted root growth, and even seedling death.

2. Cadmium (CD).

Excessive levels of cadmium in the soil can lead to excessive accumulation of cadmium ions in plant leaves, which in turn leads to slow plant growth, poor nutrient absorption, and stunted growth.

3. Mercury (Hg).

High concentrations of mercury ions may directly enter the plant body, resulting in yellowing of leaves, poor growth, and obvious inhibition of photosynthesis and respiration in plants.

4. Nickel (Ni).

High concentrations of nickel can interfere with nutrient absorption and material transport in plants, resulting in slow plant growth and reduced pigment synthesis, leading to death.

5. Other heavy metals.

Excessive levels of heavy metals such as chromium (Cr), manganese (Mn), zinc (Zn), and copper (Cu) can cause varying degrees of damage to plants.

In short, excessive heavy metals in high absolute soil will have a great impact on the growth and development of plants, and seedlings have not yet formed a sound root system and leaves, which is more susceptible to heavy metal hazards and death. Therefore, soil testing must be carried out before planting site, and if it exceeds the standard, corresponding measures should be taken to deal with it, such as physical and chemical methods, to ensure the growth and health of the plant.

Heavy metals are metal elements that have a high density and atomic weight compared to other metals. Although heavy metals are a long-lasting element in nature, the impact of human activities such as industry and mining has led to the release of heavy metals into the soil environment, which has seriously affected soil quality and ecological health. The following analyzes the impact of heavy metals on the soil environment from the following aspects:

1. Toxic effect.

Heavy metals are easy to accumulate in the soil environment and are not easy to decompose, and if they reach a certain concentration, they are easy to cause toxic effects on the Kunchang first insects, pests, microorganisms and other ecosystems, thereby disturbing the ecological balance and not conducive to the recycling and transformation of substrates.

2. Toxic transformation.

Heavy metals are prone to highly toxic mineral transformation in the soil environment, resulting in soil pollution. For example, chromium is considered a toxic substance to most bacteria and plants, while lead is also a highly harmful metal to humans.

3. Seed germination and root growth are affected.

Heavy metals will affect the physical and chemical properties of the soil, thereby affecting the air permeability of the soil, which can easily lead to the decline of seed germination rate and the inability of roots to grow normally, thereby affecting the growth and development of plants.

4. Destruction of soil micro-ecosystems.

Soil microecosystem is an important part of the soil, and the bacteria and fungi present in the soil play an important role in the life activities of many living organisms. However, heavy metal pollution will destroy the habitat and life form of these microorganisms, thus affecting the survival and reproduction of microorganisms.

5. The cumulative effect of heavy metals.

Heavy metals are often absorbed by organisms in the soil in the form of accumulation, which will produce the phenomenon of "genetically modified", resulting in an increasing concentration of heavy metals in the soil, and then gradually migrating in the environment, which will eventually form large-scale environmental pollution.

In summary, the heavy gold rotation has a great impact on the soil environment, which also seriously affects the quality and ecological health of the soil. If it is not effectively prevented and controlled, it will have a negative impact on human society and the ecological environment. Therefore, targeted measures need to be taken to improve the soil environment and reduce the potential danger of heavy metals and other harmful substances to soil, ecosystems and humans.

Contained. The availability of nutrients such as zinc, copper, manganese, iron, and boron in soil generally increases with the decrease of soil pH, but molybdenum is the opposite. Too much and not enough ions in the soil can also have a negative impact on soil fertility.

If calcium ions are insufficient, the stability of soil aggregates will be reduced, and their structure will be destroyed, and the permeability of the soil will be reduced. Too many aluminum and hydrogen ions will cause the soil to react acidically and produce aluminum ion poisoning. Too much sodium ion will cause alkaline reaction and sodium ion poisoning in the soil, which is not conducive to plant growth.

The fertility of soil nutrients should focus on changes in chemical substances, and whether the results reflected are beneficial for the long-term growth of plant species!