What can affect downstream water quality related to nutrient management?

• A. Only organic nutrients affect water quality.
• B. Nutrients always stay in the field.
• C. Water quality is unaffected by nutrient management.
• D. Soluble nutrients can be transported in surface or tile drainage water off-site.

Answer: (C)

Managing nutrients affects downstream water quality because soluble forms can move with water after application. When rainfall or irrigation occurs, these soluble nutrients can dissolve in the moving water and be carried away through surface runoff or through tile drainage systems. This off-site transport means nutrients can reach streams, rivers, or lakes, potentially causing problems like algal blooms or water quality degradation downstream. It’s not just organic nutrients that matter; inorganic soluble nutrients contribute as well. They don’t always stay in the field, and assuming water quality is unaffected by how nutrients are managed isn’t accurate. The statement that best reflects the reality is that soluble nutrients can be transported in surface or tile drainage water off-site.