ABSTRACT
Scarcity of nitrogen (N) is the most widely occurring nutritional limit on the productivity of crops across the word. Nitrogen is also the element most widely over applied to agricultural crops and the most widely responsible for water quality. Phosphorus (P) is the second most widely limiting nutrient after nitrogen. Potassium (K) is absorbed by the plants in larger amounts than any other nutrient except N. Potassium is a unique element in the sense that plant can accumulate it in abundant amounts without exhibiting any toxicity symptoms. Nickel is the latest nutrient to be established as an essential nutrient to higher plants. Copper is a transition element existing in the plant as a component of large number of proteins and enzymes. Molybdenum is the only heavy transition metal taken up by the plants as molybdate ion. Sodium, Silicon, cobalt, selenium and vanadium are the beneficial elements.
