Certified Crop Advisor Practice Exam

Which pollutant in water is not commonly linked to agriculture?

1. Nitrate

2. Phosphate

3. Mercury

4. Herbicides

The correct answer is: Mercury

Mercury is not commonly linked to agriculture as a significant pollutant in water compared to the other options. While agriculture can contribute to water pollution through nutrients and chemicals such as nitrates, phosphates, and herbicides, mercury is primarily associated with industrial processes and atmospheric deposition. It often originates from sources such as mining, coal combustion, and other industrial activities rather than from traditional agricultural practices. Nitrates and phosphates are frequently linked to agricultural activities due to their use in fertilizers which, when washed away during rainfall, can lead to water pollution and eutrophication of aquatic systems. Similarly, herbicides are chemicals applied to crops to control weeds, which can also contaminate water bodies through runoff. Mercury's presence in water systems typically originates from non-agricultural sources, making it a less relevant concern within the context of agricultural pollution. Understanding these distinctions helps in managing water quality and addressing the specific sources of pollutants more effectively.