Classification of Plant Nutrients

1. Basic Nutrients:

• The basic nutrients viz. carbon, hydrogen and oxygen constitute 94% of total dry matter of plants.
• Among them carbon constitute 45%, hydrogen (6%) and oxygen (43%).

2. Macronutrients:

• Elements which are required by plants in considerable concentrations (greater than 1 ppm) are called macronutrients
• Eg. C (45%), H (6%), O (43%) which are used by plants from air and water constitute 94%, N (1-3%), P (0.005-1%), K (0.3-6%), S (0.05-1.5%), Ca (0.1-4%), Mg (0.004-1%).

3. Micronutrients:

• Elements, which are required by plants in minute quantities (0.001-1000 ppm) or plants also take them up in considerable amounts are termed micronutrient or trace elements e.g. Mn, Cu, Zn, B, Mo, Cl, and Fe.
• Some beneficial nutrients important for some plants are sodium (Na) eg. For sugarbeets and silicon (Si) e.g. for cereals (strengthening cereal stems to resist lodging), cobalt (Co) e.g. required in the process of N fixation of legumes and vanadium (V) for green vegetables.