Two nutrients needed by plants in largest amounts are N and

Two nutrients needed by plants in largest amounts are N and Potassium.
Elements used in large quantities by the plant are termed macronutrients, which can be further defined as primary or secondary. The primary nutrients include nitrogen (N), phosphorus (P) and potassium (K).
Potassium is involved in the regulation of water and the transport of the plant’s reserve substances. It increases photosynthesis capacity, strengthens cell tissue, and activates the absorption of nitrates.