Effects of Controlled Irrigation and Drainage on Nitrogen and Phosphorus Concentrations in Paddy Water

Table 2

Mean TP, -N, and -N concentrations in surface water at different stages.

Form of N and P (mg⋅L^−1)	Treatments	Tillering stage (stage I)	Jointing-booting stage (stage II)	Panicle initiation stage (stage III)	Milky stage (stage IV)
-N	FFTD	6.20	2.59	4.82	1.53
	FDTF	7.27	3.31	5.62	1.93
-N	FFTD	2.01	1.31	2.04	0.88
	FDTF	3.14	2.07	2.63	1.23
TP	FFTD	0.16	0.10	0.06	0.03
	FDTF	0.25	0.16	0.96	0.47

Note: mean values in the same row followed by the same letter show nonsignificant difference. FDTF indicates first drought and then flooding; FFTD indicates first flooding and then drought.