Using nitric acid for pH adjustment provides what additional benefit?

• A. It provides nitrogen to the plants
• B. It increases potassium uptake
• C. It lowers soil salinity
• D. It acts as a pesticide

Answer: (A)

Using nitric acid to adjust pH provides an extra benefit: it supplies plant-available nitrogen in the nitrate form. Nitrogen is essential for growth, and nitrate is readily taken up by roots and used to build amino acids, proteins, and chlorophyll. So, besides lowering pH, nitric acid contributes nitrogen to the plant. The other options don’t fit because adjusting pH with nitric acid doesn’t inherently increase potassium uptake, lower salinity, or act as a pesticide.