Fertilizers are used to obtain higher yields of crops. However, all nutrients are usually not available in fertilizers. Which one of the following nutrients is usually not available in fertilizers?
Fertilizers are primarily used to supply essential nutrients to plants, most commonly Nitrogen (N), Phosphorus (P), and Potassium (K), known as macronutrients. While plants also require micronutrients like Iron (Fe), Manganese (Mn), Zinc (Zn), Copper (Cu), Boron (B), Molybdenum (Mo), and Chlorine (Cl), standard or general-purpose fertilizers usually focus on NPK. Iron is a micronutrient and is not always available in all standard fertilizer formulations, though it may be included in specific micronutrient mixtures or specialized fertilizers.
Nitrogen, Phosphorus, and Potassium are the primary nutrients universally found in common fertilizers. Iron is a micronutrient whose availability varies depending on the fertilizer type and the specific needs of the soil and crop.
Macronutrients (N, P, K) are required by plants in larger quantities, while micronutrients (like Fe) are needed in smaller amounts. While important for plant health, the question asks which one is *usually not available* in fertilizers, implying it’s not a guaranteed component unlike N, P, or K in most standard products.