The three primary soil micro-nutrients are
[amp_mcq option1=”carbon, oxygen and water” option2=”copper, cadmium and carbon” option3=”nitrogen, phosphorus and potassium” option4=”boron, zinc and magnesium” correct=”option3″]
This question was previously asked in
UPSC CAPF – 2013
Plants require various nutrients from the soil for healthy growth. These are broadly classified into macronutrients (needed in larger quantities) and micronutrients (needed in smaller quantities). The three most crucial macronutrients, often called primary nutrients, are Nitrogen (N), Phosphorus (P), and Potassium (K). While the question asks for “micro-nutrients”, option C lists the standard “primary” nutrients. Given the options, NPK is the only plausible set of primary nutrients listed.