Research Article

The Effects of Controlled Drainage on N Concentration and Loss in Paddy Field

Table 2

Design of PFCD water level and controlled periods in 2010.

Growth stageTillering stageJointing-booting stageHeading-flowering stageMilking stage

Growth date (month/day)Jul 05~Aug 05Aug 06~Aug 26Aug 27~Sep 09Sep 10~Sep 22
Control date (month/day)Jul 19~Jul 28Aug 14~Aug 23Aug 30~Sep 08Sep 12~Sep 21
Surface water level or subsurface water table depth (mm)
 W1120 (2 mm/d)−300~30−300~30−300~30
 W2120 (4 mm/d)−300~30−300~30−300~30
 W3−200~20250 (2 mm/d)−300~30−300~30
 W4−200~20250 (4 mm/d)−300~30−300~30
 W5−200~20−300~30250 (2 mm/d)−300~30
 W6−200~20−300~30250 (4 mm/d)−300~30
 W7−200~20−300~30−300~30250 (2 mm/d)
 W8−200~20−300~30−300~30250 (4 mm/d)
 CK−200~20−300~30−300~30−300~30

Note: bold types indicate paddy field controlled drainage treatments at different stages, the left numeral is paddy water level, and the numeral in parentheses is drainage intensity under control. Minus sign represents subsurface water table depth.