If groundwater flow is significantly below the root zone, what is likely to occur regarding nitrate?

When groundwater flow is significantly below the root zone, it means that the water, along with any dissolved substances like nitrate, is not easily accessible to plant roots in the upper soil layers. In this situation, nitrate is unable to be taken up by plants efficiently.

In saturated or anaerobic conditions deep below the root zone, the processes that typically facilitate the removal of nitrate, such as plant uptake or denitrification, are diminished. Denitrification, which is the conversion of nitrate to nitrogen gas by microorganisms, is more likely to occur in well-oxygenated and shallow soils. Therefore, with limited flow in the groundwater below the root zone, the movement of nitrate into the upper soil layers is hindered, and biological processes to remove it are not effectively engaged.

This results in the retention of nitrate at lower depths where it cannot be assimilated by plants, making it more stable and sometimes leading to a buildup in those deeper layers. Thus, the answer that nitrate will not be effectively removed aligns with the understanding of groundwater dynamics and nutrient cycling in relation to root accessibility.