Types Of Fertilizers
Fertilizers are substances that are either added to the soil or applied directly to plants to enhance the growth and strength of plants. Most importantly these substances are added to the soil to make the soil more fertile in general so the plants that grow on it are strong and have all the major nutrients.
In nature plants grow by taking up nutrients along with water from the soil. These nutrients are required by plants to perform various functions and to grow. At times many nutrients for example nitrogen, which is essentially required by the plants may not be rich in soil or may not be present at all.
To compensate the loss fertilizers are applied to the soil, these fertilizers then provide the plants with all the nutrients that they require. Mostly these fertilizers provide plants with secondary nutrients such as phosphates, nitrates, calcium and sulfates as these compounds are not abundant naturally in the soil.
Fertilizers are basically of two types:
- Organic fertilizers
- Inorganic fertilizers
Organic fertilizers are the natural fertilizers. These fertilizers have been used by man for thousands of years and are the most common type of fertilizers. These include compost, manure, seaweed, peat moss and guano.
Organic fertilizers are safe to use and don’t cause damage to the plant. Manure has been the most common type of natural fertilizer used by man. It is a mixture containing animal dung and is always applied on the soil to produce better crops.
To provide plants with sufficient nitrogen even dried blood is applied at times to the soil. Another common type of organic fertilizer is bone meal which is also incorporated into the soil by farmers.
Organic fertilizers have numerous benefits with the most important being that they are natural and do not cause damage to the plant. But despite of that chemical or inorganic fertilizers are applied to the soil for the better growth of the plant. The first most important reason for that is these fertilizers have a very slow release. For example a nitrogenous organic fertilizer would basically enhance the function of the nitrogenous bacteria present at the root nodules.
These bacteria then through nitrogen fixation provide nitrogen to the plant. Also they are not as reliable in providing maximum nutrients as compared to the inorganic fertilizers. But none the less, natural organic fertilizers increase the physical and biological absorption mechanism of soil which is very essential for plant growth.
Inorganic fertilizers are also called chemical fertilizers. These fertilizers are either made artificially or obtained naturally. Mostly inorganic fertilizers are a mix of various chemicals made to enhance the nutrient concentration of the soil.
Inorganic fertilizers have many advantages over organic fertilizers; firstly they are not bulky and act fast.
They are easily transported and are much reliable when it comes to nutrient concentration. However they may cause plant burning and if the right fertilizer is not chosen they may be detrimental to the plant.
Inorganic fertilizers are sold in granular, powdered or liquid forms. There are three major categories of inorganic fertilizers based on three major types of nutrients namely: phosphorus, nitrogen and potassium.
Some commonly used inorganic fertilizers are:
Ammonia is a gas but is applied in the liquid form to the plants to enhance the nitrogen content of the plant.
Basically ammonia is applied to the irrigation water. The only problem is that ammonia is an expensive fertilizer.
Sodium nitrates are another common fertilizers used for nitrogen enhancement. These fertilizers contain up to 16% nitrogen and they are immediately taken up by the plants.
They must be applied to the soil while plants are growing. The only disadvantage that they have is that when used in excess they may cause deflocculation.
Powdered rock phosphate is an ideal fertilizer to be used in soils that are slightly acidic and are phosphorus deficient. They contain up to 25-35% of phosphorus and if there is an ample amount of rainfall these fertilizers result in long growing and healthy plants. However rock phosphate is not easily soluble in water and has to be crushed before use.
Muriate of Potash
Muriate of potash is a commonly used fertilizer for potassium. It consists up to 50-60% potassium and is sold in a gray crystal. This fertilizer should be applied on the soil before sowing the plant.