2.3.19 (HL)—Denitrification conditions

Waterlogging reduces oxygen diffusion, favouring denitrification and leaching that remove plant-available nitrogen.

Low oxygen lets denitrifiers use nitrate and return N₂; moving water can carry nitrate away. Some insect-eating plants supplement nitrogen but still photosynthesize for carbon and energy.

After heavy rain, a saturated field may show falling nitrate and poorer crop growth even though total nitrogen remains in the wider system.

It changes oxygen and water movement, which changes denitrification and leaching rates.

Waterlogging does not destroy nitrogen; it changes chemical form or moves it out of root access.