ABSTRACT
Chemical fertilizers are most widely used to provide supplemental nutrition to crops. They are popular due to several of their advantages, despite having disadvantages. The major inorganic fertilizers are nitrogen and phosphorus, supplied as NPK with different ratios. Problems associated with use of inorganic fertilizers are trace mineral depletion, overfertilization, high-energy consumption, and negative environmental effects. Mode and time of application of fertilizers and manures are very important. Diagnosing the fertilizer needs of soils must do before fertilizer application. Fertilizer application calculations are generally followed for the major nutrients (NPK). It is very important to know the best time to apply the specific type of fertilizer a plant requires. The placement of nutrients is an important issue in nutrient management. Liquid form of fertilizers are applied as starter solution, foliar application, direct application to the soil, and application through irrigation water. Crop nutrient uptake rate is different at each growth stage, crop type, and growing condition. The keys to effective crop nutrient management are developing and following a yearly plan, and conducting soil tests. It is essential to keep good records on the rate, method, and timing of all nutrient applications and to follow a soil specialist's recommendations.
