Final answer:
Fertilizers are substances that provide essential nutrients to plants, including macronutrients like Nitrogen, Phosphorus, and Potassium, which are crucial for various aspects of plant growth. Farmers use fertilizers to increase plant growth and crop yield. Fertilizers come in different formulations, and the NPK rating indicates the proportions of key nutrients.
Step-by-step explanation:
Fertilizers in Agriculture
A fertilizer is a substance that provides essential nutrients to plants. There are three main macronutrients that are essential for plant growth: Nitrogen (N), which promotes leaf growth; Phosphorus (P), important for the development of roots, flowers, seeds, and fruits; and Potassium (K), which is vital for strong stem growth, the movement of water in plants, and the promotion of flowering and fruiting. Besides these, there are secondary macronutrients like calcium (Ca), magnesium (Mg), and sulfur (S), as well as micronutrients that include copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn), and boron (B).
Farmers use fertilizers to improve plant growth and increase crop yield. For example, nitrogen is often added because it's a limiting factor of plant growth in most terrestrial ecosystems. Likewise, phosphorus is used to enhance the production of organic compounds. Commercial fertilizers come in various formulations, including single-nutrient and multi-nutrient fertilizers such as NP, NK, PK, and NPK, which include a combination of nitrogen, phosphorus, and potassium. The NPK rating system informs us about the proportion of these nutrients in a fertilizer, with the numbers representing the percentage weight of nitrogen, phosphorus (as P2O5), and potassium (as K2O) respectively.