Effect of nitrogen fertilizer rates on grain yield and nitrogen uptake and use efficiency of bread wheat (Triticum aestivum L.) varieties on the Vertisols of central highlands of Ethiopia

Table 3 Mean squares of combined analysis of variance for the effects of year, N rate and variety on grain yield, grain nitrogen concentration (GNC), straw nitrogen concentration (SNC), grain nitrogen uptake (GNUP), total nitrogen uptake (TNUP), agronomic efficiency (AE), agro-physiological efficiency (APE), recovery efficiency (RE) and nitrogen harvest index (NHI) at Enewari, central highlands of Ethiopia

	Mean squares for sources of variation with respective degrees of freedom in parenthesis
Parameter	Y (1)	Rep (Y) (6)	N (3)	V (2)	N×V (6)	Y×N (3)	Y×V (2)	Y×N×V (6)	Error (66)
GY	1,062,684**	23,718	64,523,847**	6,214,722**	1,240,489**	188,153**	1,120,317**	624,803**	39,103**
GNC	0.16*	0.013	2.38**	0.53**	0.07**	0.04*	0.31**	0.01NS	0.01
SNC	0.021**	0.001	0.143**	0.031**	0.012**	0.001NS	0.003NS	0.003NS	0.001
GNUP	50.63 ns	22.36	41,509.00**	5241.11**	858.91**	173.17**	26.39 ns	391.82**	27.6
TNUP	1611.76**	19.44	69,011.00**	4385.22**	1018.49**	456.28**	19.75NS	396.92**	38.12
AE	15.38*	1.53	2531.80**	39.82**	10.44**	5.64**	25.12**	4.39**	1.03
APE	33.12*	6.48	7744.88**	102.85**	36.68**	17.59**	111.22**	13.56**	3.60
RE	0.024**	0.00042	1.53**	0.069**	0.01**	0.0078**	0.0018NS	0.0036**	0.0008
NHI	0.0655NS	0.0014	0.0299*	0.0523**	0.0045**	0.0002 ns	0.0002 ns	0.0029 ns	0.0012

Y year; N nitrogen rate; V variety
*Significant at the 0.05 probability level; **Significant at P < 0.01 probability level

ISSN: 2048-7010