Effect of Irrigation and Preplant Nitrogen Fertilizer Source on Maize in the Southern Great Plains

Table 4

value results from the analysis of variance for the main and interactive effects of irrigation (Irr.) and preplant fertilizer treatment (Tmt.) on grain yield, N use efficiency (NUE), and water use efficiency (WUE).

Source	Grain yield	NUE	WUE
STW^a 2012
Irrigation	0.0150	0.2258	—
Treatment	0.2241	0.6263	—
Irr. × Tmt.	0.0544	0.1089	—
LCB^a 2012
Irrigation	0.0118	0.9156	—
Treatment	0.1355	0.0145	—
Irr. × Tmt.	0.3038	0.0394	—
STW 2013
Irrigation	0.0034	0.2243	0.0037
Treatment	0.0221	0.0381	0.0283
Irr. × Tmt.	0.1036	0.3306	0.1190
LCB 2013
Irrigation	0.0440	0.0415	0.0498
Treatment	0.0370	0.2215	0.0319
Irr. × Tmt.	0.5533	0.7275	0.4957

STW: Stillwater, OK; LCB: Lake Carl Blackwell, OK.