Plants require nutrients or elements obtained from the soil for good growth and healthy development. These elements or nutrients are classified into two main groups which are:
- Macro-Nutrients: Macro-nutrients are mineral elements or nutrients required by crops in large quantities. Examples of macro-nutrients are nitrogen, phosphorus, potassium, magnesium, calcium and sulphur.
- Micro Nutrients or Trace Elements: Micro nutrients are mineral elements or nutrients required by crops in small quantities. Examples of micro-nutrients are zinc, copper, boron, molybdenum, iron, chlorine and manganese.
The functions and deficiency symptoms of these elements or nutrients are summarised below:
- It aids plants’ growth and reproduction because it is an essential constituent of all proteins.
- It increases the size of grain in cereals or carbohydrate synthesis.
- It promotes vegetative and short system growth.
- Excess nitrogen delays maturation and fruiting.
- It promotes uptake of potassium and phosphorus from the soil.
- It promotes chlorophyll formation or deep green colour of leaves.
- It is necessary for the synthesis of plant hormones/ enzymes/ auxins.
- Stunted growth.
- Yellowing of leaves (Chlorosis).
- Leaves tend to drop.
- Poor formation of fruits and flowers.
- It aids enzyme reactions.
- It is a constituent of cell nucleus and essential for cell division.
- It increases crop resistance to diseases.
- It helps in ripening of fruits.
- It helps in root development, seed germination, fruit formation and maturity.
- It aids seed germination.
- It aids fruit formation and maturity.
- It improves the good taste of forages and vegetables.
- Logging results in cereal crops.
- Leaves turn to purple and brownish colouration from tip backwards.
- Stunted growth.
- Inhibition of flowering, fruits and seed formation.
- Poor root development.
- Immature fruit drop.
- It is an important constituent of plant tissues.
- It aids synthesis of carbohydrate.
- It activates various plant enzyme reactions.
- It promotes the development of young plants.
- It is necessary for neutralisation of organic acids in plants.
- It is associated with stomata movement and therefore influences water relationship within the plant.
- It is a major constituent of plant tissue.
- It helps in nitrate uptake from the soil.
- Weak slender stems
- Delayed growth
- Premature loss of leaves
- Brown colour at margin of leaves.
- It strengthens plant cell walls with calcium pectate.
- It helps in the translocation and storage of carbohydrate and proteins into seeds and tubers.
- It controls the toxicity of aluminium manganese and sodium ions.
- It is necessary for the normal growth of root tips.
- It strengthens plant cell walls.
- It helps in high flocculation i.e. good aeration, water infiltration and retention.
- It improves the pH of the soil so that nitrogen fixation can be carried out.
- It causes stunting of the root system
- There is appearance of pale yellow colour in the leaves.
- Weak slender plants.
- It is important in the synthesis of carbohydrate as it is a constituent of chlorophyll.
- It assists in the transportation of phosphate, an essential material to developing fruit seeds.
- It enhances plant growth.
- It is required for normal cell division.
- It is necessary for synthesis of oils in plants.
- Chlorosis along the leaf veins.
- Stunted growth.
- Premature leaf-fall.
- It is a constituent of plant proteins since it occurs in some amino acids such as cystine and methionine.
- It is also a constituent of plant hormones such as biotein and thiamine.
- It is essential for chlorophyll formation.
- It is also required for carbohydrate metabolism and nitrogen fixation by legumes.
- Yellowing of leaves.
- Stunted growth.
- Poor rate of photosynthesis.
- It is necessary for chlorophyll formation.
- It is necessary for protein synthesis contained in chloroplasts.
- It is important in enzyme systems associated with oxidation and reduction reactions.
- Chlorotic condition in leaves, which becomes pale green.
- It is a constituent of enzymes which are responsible for protein synthesis.
- It is important for certain nitrogen transformation in plants and microorganisms.
- Young leaves shows pale greenish yellow discolouration between veins.
- It is a constituent of certain enzymes
- It is necessary for photosynthesis.
- It is involved in respiration and utilization of iron.
- Pale green colour of leaves.
- The tips of older leaves dry off and die.
- Young leaves tips die back.
- It is involved in the action of certain enzymes.
- Production of mottled or extremely small leaves.
- It is an important nutrient in protein synthesis.
- It facilitates the development of roots.
- It assists in the formation of fruits and seeds.
- It encourages the division of cells in the growing regions of plants.
- It increases yield.
- It facilitates nodulation in leguminous plants.
- It causes the death of tips of roots and shoots.
- Failure of flower buds to develop.
- It causes poor growth of plants.
- It causes breaking or lodging.
- It decreases the rate of water absorption and translocation of sugars.
- It aids nitrogen fixation acids and proteins.
- It is an essential part of enzymatic system involved in facilitating nitrogen change, breakdown of leaf edges.
- Promotes metabolism of nitrates into amino acids and proteins.
- It causes mottled leaves.
- It leads to curling.
- It causes premature flower drops.