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 stage
Tillering stage
Jointing-booting stage
Heading-flowering stage
Milking stage
Growth date (month/day)
Jul 05~Aug 05
Aug 06~Aug 26
Aug 27~Sep 09
Sep 10~Sep 22
Control date (month/day)
Jul 19~Jul 28
Aug 14~Aug 23
Aug 30~Sep 08
Sep 12~Sep 21
Surface water level or subsurface water table depth (mm)
W1
120 (2 mm/d)
−300~30
−300~30
−300~30
W2
120 (4 mm/d)
−300~30
−300~30
−300~30
W3
−200~20
250 (2 mm/d)
−300~30
−300~30
W4
−200~20
250 (4 mm/d)
−300~30
−300~30
W5
−200~20
−300~30
250 (2 mm/d)
−300~30
W6
−200~20
−300~30
250 (4 mm/d)
−300~30
W7
−200~20
−300~30
−300~30
250 (2 mm/d)
W8
−200~20
−300~30
−300~30
250 (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.