Which statement about nitrate mobility is most accurate?

• A. Nitrate mobility is limited by soil texture.
• B. Nitrate leaches only in sandy soils.
• C. Nitrate is easily leached because both nitrate and soil particles are negatively charged.
• D. Nitrate never moves with water.

Answer: (C)

Nitrate moves with water because of its chemistry: it is a negatively charged ion (an anion), and most soil surfaces also carry negative charges. This repulsive interaction means nitrate isn’t held tightly by soil particles, so it isn’t adsorbed or retained well. As water infiltrates or percolates through the soil, nitrate readily accompanies that water downward, leading to leaching. This can happen in any soil with enough drainage and percolation—sandy soils often show faster leaching due to quicker water movement, but leaching isn’t limited to sandy soils. Nitrate clearly does move with water, so stating that it never moves is incorrect.