Zinc deficiency is the most ubiquitous micronutrient deficiency problem in world crops. Because it is the building block of the structure and regulator of enzymes and proteins in the central nervous system. Providing the required amount of zinc to plants as the most important source of zinc supply is inevitable. Zn deficiency results in severe yield losses and in acute cases plant death.
Millions of hectares of cropland are affected by Zn deficiency and approximately one-third of the human population suffers from an inadequate intake of Zn. The main soil factors affecting the availability of Zn to plants are low total Zn contents, high pH, high calcite and organic matter contents and high concentrations of Na, Ca, Mg, bicarbonate and phosphate in the soil solution or in labile forms. Zinc fertilizers are used in the prevention of Zn deficiency and in the biofortification of cereal grains. In the following, we will get acquainted with the importance of zinc and its side effects in plants and humans.
The function of zinc in the human body
Zinc is an organic and nutrient that plays a vital role in many functions of the human body. Since the human body is not naturally able to produce zinc, it must be obtained through food or supplements. Zinc is the second most rare mineral in the human body after iron. Plant Resources The best sources of zinc required for this substance are essential for the activity of more than 300 enzymes that aid in the metabolism, digestion, functioning of the nervous system and many other processes. In addition, zinc also plays an essential role in the following cases:
- Growth and function of the immune system
- Skin and hair health
- Body development
- Health of taste and smell
- DNA synthesis
- Wound healing
- Production of essential proteins of the body
- Enzymatic reactions
- Reduce the risk of age-related diseases such as pneumonia, infection and age-related macular degeneration
- Reduce oxidative stress and increase the immune response
- Increase mental function
- Reduce inflammation
Symptoms of zinc deficiency in humans
It is estimated that around 2 billion people worldwide are deficient in zinc due to inadequate dietary intake. zinc deficiency is thought to cause over 450,000 deaths in children under 5 every year. Symptoms of severe zinc deficiency include:
- Developmental disorders
- Delay in puberty
- Skin rash
- Chronic diarrhea
- Impaired wound healing
- behavioral problems
- Weakening of the immune system
The importance of zinc in plant growth
The function of zinc is to help the plant produce chlorophyll. Zinc activates enzymes that are responsible for the synthesis of certain proteins. It is used in the formation of chlorophyll and some carbohydrates, conversion of starches to sugars and its presence in plant tissue helps the plant to withstand cold temperatures. Zinc is essential in the formation of auxins, which help with growth regulation and stem elongation. Leaves discolor when the soil is deficient in zinc and plant growth is stunted. Zinc deficiency causes a type of leaf discoloration called chlorosis, which causes the tissue between the veins to turn yellow while the veins remain green. Chlorosis appears on the lower leaves first, and then gradually moves up the plant. In severe cases, the upper leaves become chlorotic and the lower leaves turn brown or purple and die. When plants show symptoms this severe, it’s best to pull them up and treat the soil before replanting.
How to diagnose zinc deficiency in the plant
It’s hard to tell the difference between zinc deficiency and other trace element or micronutrient deficiencies by looking at the plant because they all have similar symptoms. The main difference is that chlorosis due to zinc deficiency begins on the lower leaves, while chlorosis due to a shortage of iron, manganese, or molybdenum begins on the upper leaves. The only way to confirm your suspicion of a zinc deficiency is to have your soil tested.
Compensation for zinc deficiency in plants
Zinc is found in most water soluble fertilizers at rates that should prevent its deficiency, unless fertilizer is not applied. Single element fertilizers such as zinc sulfate, zinc ammonium nitrate or chelated zinc can be applied; however, it is better to use a complete micronutrient fertilizer to avoid nutrient imbalances that could lead to deficiencies of other micronutrients.