Table 2.

The root distribution characteristics (g m^-2) of winter wheat under different treatments.

	Jointing stage			Flowering stage
Treatments	0-20	20-40	40-80	0-20	20-40	40-80
CK	182.2b	51.3b	2.8a	242.8a	79.8a	5.1a
I1	198.3a	49.2c	1.7b	232.6b	74.3b	4.4b
I2	176.8c	53.4a	2.7a	218.3c	78.6a	5.9a

Different letters within a column imply significant differences between different treatments at P< 0.05. CK: traditional irrigation and fertilization methods; I1: surface drip fertilization; I2: subsurface drip fertilization.