Which type of fertilizer contains the three macronutrients?

The correct answer is complete fertilizer, as it is specifically designed to provide all three essential macronutrients: nitrogen, phosphorus, and potassium (often referred to as N-P-K). These macronutrients play crucial roles in plant growth; nitrogen is vital for leaf and stem development, phosphorus is important for root growth and flowering, and potassium helps with overall plant health, water regulation, and disease resistance.

Complete fertilizers are formulated to meet the nutritional needs of plants in a balanced manner, ensuring they receive all the necessary elements for robust growth. This comprehensive approach is what distinguishes complete fertilizers from other types, which might lack one or more of these crucial nutrients.

Special purpose fertilizers may be tailored for specific plants or growth conditions but may not contain all three macronutrients. Slow release fertilizers release nutrients over an extended period but also do not necessarily guarantee the inclusion of all three macronutrients. Incomplete fertilizers, by definition, do not provide all the essential macronutrients needed for optimal plant growth, which directly leads to deficiencies if used as the sole nutrient source.