India with world second largest population is always under pressure on food security. Fertilizer plays a key role in ensuring agriculture productivity ensuring to face challenges in terms of shrinking cultivable land. Indian agriculture needs 16 elements in larger measure and 7 elements in micro measures. The first are classified as primary nutrients viz . sodium, potassium, phosphorous, nitrogen etc., These nutrients are essential to make the soil fertile and to overcome any deficiency. Some chemical fertilizers used are ammonium sulphate, calcium ammonium nitrate etc.,
Even a deficiency in micro nutrients will affect the absorption of primary nutrients. Iron, zinc, manganese, copper, boron, molybdenum and chlorine are a group of ‘micro nutrients’ which are required by the plants in small quantities. Intensive cropping deplete all nutrients including micro nutrients from the soil at a fast rate. Therefore selective use of micro nutrients is necessary for increasing agricultural production.
India has 56 large fertilizer units which produce a wide range of nitrogenous and phosphates/ complex fertilizers. Of these, 30 units produce urea; 21 units produce DAP and complex fertilizers; 5 units produce low analysis straight nitrogenous fertilizers; and 9 units produce ammonium sulphate as a by-product.