Fertilizers are substances added to the soil to improve the amount of nutrients in the soil. Nitrogen, phosphorus and potassium are three main elements that a plant cannot grow without. Most widely available fertilizers contain nitrogen, phosphorus and potassium, the chief building blocks of plant nutrients, along with 15 to 20 other elements. Fertilizers are used to make up for the deficiencies of poor or depleted soil.
Nitrogen is one of the macronutrients found in most packaged fertilizers. It is a major component in proteins, hormones and enzymes and is essential for plant life. Plants cannot absorb nitrogen from atmosphere. Plants get nitrogen from soil from dead and decaying organic matter or through fertilizers. Nitrogen deficiency can cause abnormal growth, yellowing of leaves and death of the plant. Too much nitrogen is not good and can delay or prevent flowering.
Phosphorus is necessary for major aspects of growth, metabolism, photosynthesis and protein formation. It is essential for flowering. Phosphorus comes from recycling of dead matter and needs to be supplemented through fertilizers. Phosphorus deficiency can lead to premature loss of flowers, poor flower production, slow growth and purple leaves.
Potassium makes up 1 to 2 percent of the weight of any plant. It is essential for metabolism, sugar formation, starches, carbohydrates, protein synthesis and cell division. Potassium is also responsible for enhancing the colors of flowers and physical sturdiness of plants through controlled water absorption. Potassium deficiency can result in mottled leaves.
While most fertilizers are mostly made up of nitrogen, phosphorus and potassium, other nutrients may be present in smaller quantities. Calcium is one such essential component. Plants use calcium to control cell growth and division, the water content in cells and is part of the basic structure of cells. Some plants are unable to absorb nitrogen in the absence of calcium. Calcium deficiency can arrest or stop growth, distort new growth, and cause black spots on leaves.
Boron is an element present in fertilizers in small quantities. Boron is essential for cell wall formation and for calcium uptake. Boron influences functions like pollen germination, seed development, water balance and the movement of hormones. Boron deficiency can lead to stunted or irregular growth, and cracked or discolored roots.