Fertilizers - Just as we need vitamins, minerals, proteins etc. to stay healthy, similarly some elements are needed for the growth of plants too. .

The most essential elements for plant growth are nitrogen, phosphorus and potassium. Plants make their food by taking in water and nutrients from the soil and carbon dioxide from the air. However, due to repeated cultivation of plants in the fields, nitrogen, phosphorus in the soil of the fields.

These are natural substances obtained from the decomposition of dead animals and plants. Manures provide essential elements and humus to the soil, due to which the soil becomes fertile. Manure is also called organic fertilizer

These are man-made natural substances that are essential for the growth of plants. They maintain soil fertility by supplying essential nutrients (nitrogen, phosphorus, potassium etc.) to the soil. Fertilizers are also called inorganic or artificial fertilizers.

Types of Fertilizers - 

On the basis of the nutrients present in the fertilizers, we classify the fertilizers into three parts-

1) Nitrogenous fertilizer 

2)Phosphatic fertilizer

3) Potash fertilizer

nitrogenous fertilizers

Nitrogen is the most important element required for proper growth of plants. Fertilizers added to meet the deficiency of nitrogen in the soil are called nitrogenous fertilizers. Nitrogenous fertilizers include ammonium sulphate, ammonium nitrate, urea, calcium and sodium nitrate. Urea is the best fertilizer among nitrogenous fertilizers.

It contains about 47% nitrogen. In India, it is prepared in Sindri of Bihar state and Nangal fertilizer factories in Punjab state.

Phosphatic fertilizer 

Phosphorus comes next to nitrogen in the soil for a healthy crop. Phosphorus is generally taken up by plants in the form of dihydrogen phosphate ion H2PO4. Phosphorus is supplied in the soil in the form of phosphatidic fertilizers. Following is a brief description of the major phosphatidic fertilizers-

Super phosphate of lime: It is a mixture of monocalcium hydrogen phosphate and gypsum. To make it, with phosphatidic acid found in nature.

By doing this the amount of phosphorus in the soil increases. Among other phosphatic fertilizers, triple phosphate and phosphatic slag are prominent. Nitro phosphate or calcium super phosphate nitrate is a compound fertilizer that contains both essential elements phosphorus and nitrogen. It is obtained by treating phosphorite ore powder or bone ash with nitric acid found in nature.

Potash fertilizer

Potassium salts are also required in the soil for good growth and health of crops. Potash fertilizers are used to meet the deficiency of potassium salts in cultivable land. Potassium chloride (KCI), potassium sulfate (K2SO4) and potassium nitrate (KNO3) are prominent among potash fertilizers.

All these potassium salts are found in nature. Plenty of potassium is obtained by mining the rocks. It is also obtained from sea water. In order to obtain potassium salts from sea water, after separating the common salt (NaCl) from it, the residual material (maternity fluid) is fractionated.

Precautions taken in the use of fertilizers

The soil should be well irrigated after the application of fertilizers.Crops can be destroyed due to excessive use of fertilizers, so fertilizers should be used as per the need and according to the nature of the soil.