Storing and removing nitrogen in drainage from paddy field by using aquatic crops wetland

Aquatic crop (Zizania latifolia Stapf–Ipomoea aquatica Forsk) wetlands were constructed to remove nitrogen (N) in drainage from paddy rice fields, with three different storage water depths (namely 4H, 7H and 10H, where H is the routine paddy drainage water depth). Concentrations of ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3−-N) and total nitrogen (TN) during the first two drainage events were reduced within 8–14d of storing by 82.3–92.8%,...