Nitrogen Uptake Efficiency and Total Soil Nitrogen Accumulation in Long-Term Beef Manure and Inorganic Fertilizer Application
Table 2
Wheat grain yield (kg·ha−1), grain N content (%), N uptake (kg·ha−1), and total soil N (g·kg−1 soil) of Magruder Plots (1990–2015) located at Stillwater in Oklahoma, USA.
Year
Grain yield (kg·ha−1)
Grain N (%)
N uptake (kg·ha−1)
Total soil N (g·kg−1 soil)
Manure
Check
NPKL
Manure
Check
NPKL
Manure
Check
NPKL
Manure
NPKL
Check
1990
2325.1
1451.5
2184.0
2.04
2.00
2.28
47.4
29.0
49.8
0.70
0.76
0.59
1991
1753.9
1115.5
2963.5
2.33
2.04
2.44
40.8
22.8
72.2
0.70
0.76
0.59
1992
1429.2
903.2
1973.7
2.17
1.96
2.35
31.0
17.7
46.4
0.74
0.77
0.60
1993
2499.5
1259.6
2754.3
2.22
1.91
2.26
55.5
24.1
62.2
0.74
0.77
0.60
1994
1510.1
628.4
1865.4
2.23
2.34
2.39
33.6
14.7
44.7
0.95
0.99
0.62
1996
1669.2
967.7
1884.3
2.28
2.18
2.28
38.1
21.1
43.0
1.07
0.93
0.69
1997
3454.1
1397.8
4186.6
2.28
2.18
2.28
78.8
30.5
95.5
1.17
1.07
0.69
1998
2071.8
974.4
2591.9
2.31
2.03
2.43
47.9
19.8
63.0
—
—
—
1999
2744.6
1767.5
2527.9
2.31
2.50
2.32
63.3
44.2
58.7
—
—
—
2000
2473.4
1511.6
2377.7
2.25
1.80
2.12
55.7
27.3
50.3
—
—
—
2001
2563.0
795.1
2663.8
2.32
2.24
2.30
59.5
17.8
61.1
0.59
0.68
0.52
2002
2369.4
1212.0
2790.4
1.96
1.85
2.52
46.4
22.4
70.3
0.68
0.68
0.49
2005
2956.8
1209.6
2956.8
2.43
1.96
3.02
72.0
23.7
89.2
—
—
—
2006
2225.1
1414.8
3112.7
2.14
2.02
2.65
47.6
28.5
82.4
1.09
0.98
0.74
2008
3473.6
1823.5
3281.4
1.74
1.91
2.21
60.5
34.9
72.5
—
—
—
2009
166.7
330.0
357.5
2.12
1.92
2.08
3.5
6.3
7.4
1.05
0.95
0.79
2010
2313.4
1244.4
2669.3
2.51
2.60
2.81
58.1
32.3
75.1
1.05
0.95
0.79
2011
1286.8
431.9
1675.5
2.25
2.17
2.83
29.0
9.4
47.4
0.84
0.76
0.72
2012
2655.7
1022.8
3007.9
1.94
1.79
1.96
51.6
18.3
58.9
0.81
0.77
0.53
2013
2860.0
1029.5
3571.7
1.58
1.69
1.60
45.1
17.4
57.3
0.96
1.01
0.63
2014
2243.5
1161.6
2365.9
1.69
1.78
1.85
38.0
20.6
43.8
1.46
1.65
1.23
2015
3117.4
1816.1
4048.2
1.77
1.73
1.80
55.2
31.3
72.9
1.04
1.04
0.81
NPKL = nitrogen, phosphorus, potassium, and lime; check = no fertilizer applied; manure = beef manure applied every four years.
