Table 3.

Effects of plastic mulching (M), basal nitrogen application depth (D) cropping year (Y) and their interactions on maize grain yield (GY), biomass accumulation (BA), harvest index (HI), nitrogen uptake by plants (NUP), soil nitrate-N residual (NR), nitrogen loss (NL), nitrogen recovery efficiency (NRE) and nitrogen use efficiency (NUE).

Source	GY	BA	HI	NUP	NR	NL	NRE	NUE
Mulching (M)	0.01	<0.001	NS	0.013	<0.001	<0.001	<0.001	0.013
Depth (D)	<0.001	<0.001	NS	<0.001	<0.001	<0.001	<0.001	<0.001
Year (Y)	NS	NS	NS	NS	0.037	NS	NS	NS
M × D	NS	NS	NS	NS	NS	NS	NS	NS
D × Y	NS	NS	NS	NS	NS	NS	NS	NS
Y × M	NS	NS	NS	NS	NS	NS	NS	NS
M × D × Y	NS	NS	NS	NS	NS	NS	NS	NS

NS, not significant (P > 0.05).