Nitrogen Uptake Efficiency and Total Soil Nitrogen Accumulation in Long-Term Beef Manure and Inorganic Fertilizer Application

Table 3

Analysis of variance for wheat grain yield, grain N uptake, and TSN including summary of relationships between these variables in manure, check, and NPKL treatments (1990–2015) of Magruder Plots located at Stillwater in Oklahoma, USA.

Treatment	Grain yield (kg·ha^−1)		Grain N uptake (kg·ha^−1)		TSN (g·kg^−1 soil)
Treatment means
Manure (n = 22)	2265.7^A		48.11^B		0.920^A
Check (n = 22)	1165.6^B		22.82^C		0.684^B
NPKL (n = 22)	2510.5^A		60.19^A		0.913^A
Correlation coefficient
		R		R		R
Manure vs NPKL	<0.0001	0.89	<0.0001	0.84	<0.0001	0.93
Manure vs check	<0.0001	0.79	<0.0001	0.73	<0.0001	0.87
NPKL vs check	<0.001	0.67	<0.01	0.58	<0.0001	0.92

NPKL = nitrogen, phosphorus, potassium, and lime-treated plot; check = no fertilizer applied; manure = beef manure applied every four years; TSN = total soil nitrogen; treatment means within the same column with the same letter superscript are not significantly different (Tukey’s HSD test).