Denitrification is expected to be highest under which conditions?

Denitrification occurs when nitrates in the soil are converted into nitrogen gas by microbial activity, and certain conditions promote this process significantly. The highest rates of denitrification are generally found in wet, anaerobic (poorly drained) environments where microbes can thrive and have access to both moisture and nitrates.

In poorly drained soils during a wet season, water saturates the soil, creating low-oxygen conditions that favor the anaerobic bacteria responsible for denitrification. This environment allows for the accumulation of nitrates, which are easily converted to nitrogen gas, thus facilitating the denitrification process.

In contrast, well-drained soils or dry seasons do not provide the anaerobic conditions that enhance denitrification. Conventional tillage can also disrupt soil structure and reduce the anaerobic zones needed for denitrifying bacteria to be effective, leading to lower rates of denitrification.

Therefore, the combination of no-till management, a wet season, and poorly drained soil creates the most conducive setting for maximizing denitrification rates.