Mineral Nutrition
Mineral nutrition is the uptake, distribution, and metabolism of essential inorganic nutrients in a plant. These nutrients are essential for various physiological activities such as growth, repair, and photosynthesis. Mineral nutrition should be known to students because it is the foundation on which further studies on plant physiology are built.
This Story also Contains
- What is Mineral Nutrition?
- Plant Nutrient Types
- Mineral Nutrition Criteria to Determine the Essentiality of an Element
- Mineral Uptake and Absorption Process
- Nutrient Deficiency Symptoms
- Nitrogen Fixation
- Recommended videos for "Mineral Nutrition"
As more than 105 mineral elements have been identified, only around 17 are considered to be important to normal plant development and growth. This article includes types of nutrients required by plants to grow and the essentiality of a mineral nutrient with their process of uptake. The nitrogen cycle is the natural process by which nitrogen moves between the air, soil, plants, and animals in different forms.
What is Mineral Nutrition?
Mineral nutrients are the inorganic natural substances absorbed by plants from soil, water, and air. These nutrients are essential for plant growth and development. They play a major role in physiological functions within the plant, like enzyme activation, energy transfer, and cell structure formation.
Mineral - An inorganic element.
Nutrient - A substance that provides nourishment essential for the maintenance of life and for growth
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Plant Nutrient Types
The plants need both non-mineral and mineral nutrients to grow. Non-mineral elements like carbon, hydrogen, and oxygen come from air and water. Mineral nutrients are absorbed from the soil and are classified as macronutrients and micronutrients. Both are essential for plant health and development.
Type of Nutrient | Requirement | Examples |
Non-mineral elements | These form the bulk of plant biomass | Carbon (C), Hydrogen (H), Oxygen (O) |
Macronutrients | It is needed in large amounts (more than 10 mmol/kg of dry matter) | Nitrogen (N), Phosphorus (P), Potassium (K), Magnesium (Mg), Calcium (Ca), Sulfur (S) |
It is needed in trace amounts (less than 10 mmol/kg of dry matter) | Iron (Fe), Manganese (Mn), Zinc (Zn), Copper (Cu), Boron (B), Molybdenum (Mo), Chlorine (Cl), and Nickel (Ni) |
Mineral Nutrition Criteria to Determine the Essentiality of an Element
Necessary for normal growth: The element must be absolutely necessary for the plant to grow and complete its life cycle properly.
Cannot be replaced by other elements: The element’s requirement must be specific and cannot be covered by any other element's function.
Direct role in metabolism: The element should directly participate in the plant’s metabolic processes.
Example: Magnesium (Mg) is an essential mineral element that cannot be replaced by any other element, as it is a basic component of chlorophyll essential for photosynthesis and necessary as a cofactor for multiple enzymes participating in cellular respiration and various metabolic pathways.
Mineral Uptake and Absorption Process
Ions move passively from soil into spaces outside root cells as an apoplast pathway.
This rapid uptake requires no energy.
Metabolic phase:
Ions enter root cell cytoplasm and vacuoles as symplast pathways via active transport.
This phase requires metabolic energy.
After absorption, minerals and water move through the xylem vessels.
The xylem acts as a tube for transporting nutrients and water to all plant parts.
Nutrient Deficiency Symptoms
The deficiency symptoms of essential elements can be visible in plants, such as direct results of a lack of essential minerals, such as magnesium and iron, in the form of the following symptoms:
Chlorosis - yellowing of leaves due to lack of chlorophyll (seen in magnesium or iron deficiency)
Necrosis - dead patches or spots on leaves (caused by lack of calcium, potassium, etc.)
Stunted growth - the plant becomes smaller and weaker
Delayed flowering - flowers take longer to form or may not form at all
Poor root and fruit development - due to a lack of phosphorus or potassium
Falling of leaves or buds - often due to a deficiency of nutrients like zinc or boron
Nitrogen Fixation
The plants need nitrogen to grow, but they can't use it directly from the air. The nitrogen cycle helps convert nitrogen into an absorbable form through a process called nitrogen fixation. There are two main ways this happens:
Symbiotic Nitrogen Fixation: Some plants, like legumes (peas, beans) have a relationship with bacteria called Rhizobium. These bacteria live in small swellings on the roots called nodules. They take nitrogen from the air and convert it into ammonia, which the plant can use. In return, the plant gives the bacteria food and shelter.
Non-Symbiotic Nitrogen Fixation: Some free-living bacteria in the soil, like Azotobacter and Clostridium, undergo nitrogen metabolism on their own, without needing a plant partner.
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Recommended videos for "Mineral Nutrition"
Introduction to Mineral Nutrition and Hydroponics
Methods to study the mineral requirements of plants
Macronutrients and Micronutrients
Mineral nutrition is one of the very important concepts, especially for students preparing for exams like NEET, where questions on this topic very frequently come up. While studying, the students may use mineral nutrition PDFs and NCERT materials. Mineral nutrition is also a fundamental chapter in Class 11 biology; it covers the basic knowledge that will be further improvised in Class 12.
Frequently Asked Questions (FAQs)
Mineral nutrients are the inorganic natural substances absorbed by plants from soil, water, and air.
Mineral - An inorganic element.
Nutrient - A substance that provides nourishment essential for the maintenance of life and for growth
The absorption process can be broken down into two phases. In the first phase, ions are passively taken up into the apoplast, the 'free space' or 'outer space' of the cell. The ions are taken up into the symplast of the cells in the second phase of uptake - the "inner space." Ion channels are transmembrane proteins that function as selective pores that allow ions to move passively into the apoplast.
The movement of ions into and out of the symplast requires metabolic energy, which is an active process. The movement of ions is known as flux; the influx of ions into the cells and the efflux of ions out of the cells.
Yes, plants do need minerals to grow properly. The soil is a major source of nutrients needed by plants for growth.
- Chlorosis: is caused by a deficiency in potassium, sulfur, nitrogen, zinc, iron, molybdenum, and sulfur.
- Delayed Flowering: Fertilization is delayed by sulfur, nitrogen, and molybdenum deficiencies.
- Necrosis: This refers to the death of plant tissues, which is often caused by deficiencies of Ca, Mg, Cu, and K.
- Stunted plant growth: The main cause is a lack of sulfur, and Cu.
- Inhibition of cell division: This symptom results from deficiency of N, K, S, Mo
The solution is to place plants that exhibit multiple nutrient deficiencies in different sets of water cultures. The first, second, and third sets are given with three different nutrients and are grown hydroponically by supplementing one of the deficiencies. When an element is supplemented that is actually deficient, the plant will grow normally without any symptoms of deficiency.
Symptoms are determined by the mobility of a deficient element. In the presence of an immobile element, symptoms tend to occur in young parts of the plant, and in the presence of a mobile element, symptoms tend to appear in older parts of the plant.