Nitrogen Use Efficiency, Nitrogen Fertilizers, NUE, Nitrogen and the Environment Net Benefits of Using the SBNRC, Greenseeker, and OSU algorithms
    Picture Extension Technology Publications                                                  Quick links:
Use of the Greenseeker using on-the-go CV correction (Nebraska)
Brent Rendel Case Study (Oklahoma)
3-Point Trials Testing SBNRC, 2005
Jerrel Powell and Tom Denker discuss the N Rich Strip Program      Follow this Link to see Video of Farmer
           Experiences.

Table 1. Grain yield and nitrogen fertilizer applied for 2005 Wheat 3pt trial in EFAW, Lake Carl Blackwell and Tipton, OK.* UAN – 28% N

Trt

Preplant N

Topdress N*

Total N Applied, lb ac-1

Grain Yield, bu ac-1

 

    lb ac-1

 

EFAW

LCB

Tipton

EFAW

LCB

Tipton

1

0

0

0

0

0

28

42

14

2

120

0

120

120

120

35

58

45

3

0

NFOA

26

28

24

32

43

21

4

45

NFOA

53

61

64

34

54

32

5

0

SBNRC

40

58

40

33

49

27

6

45

SBNRC

60

80

85

35

57

40

7

45

45

101

87

-

36

56

-

8

90

0

90

90

-

35

59

-

 

 

 

 

 

 

 

 

 

Austin Bessie Hennesse Hydro, NT Perkins N Perkins S Ames Marshall E222 Avg. Profit
90 flat top 54 66 55 40 28 45 63 24 24 44 128.35
SBNRC-0P 54 59 52 27 25 43 59 20 23 40 135.39
40-80-120 50 44 58 45 26 45 60 25 23 42 131.51
40 flat top 50 59 52 25 25 43 66 22 20 40 127.17
Check  54 38 35 15 23 37 59 21 17 33 115.91
pre 40 60 54 45 20 23 35 56 25 27 38 121.83
pre 80 58 75 44 23 27 37 58 33 30 43 125.31
pre 120 58 62 44 42 23 41 60 34 30 44 117.15
                     
4 27 51 34 0 4 18 0 27 18  
0 40 80 80 40 40 0 80 80 49  

 

  EFAW       LCB       Tipton      
Trt Preplant Topdress Yield Profit NUE Topdress Yield Profit NUE Topdress Yield Profit NUE
  lb ac-1 lb ac-1 bu ac-1 $   lb ac-1 bu ac-1 $   lb ac-1 bu ac-1 $  
Check 0 0 28 96   0 42 147   0 14 48  
120 Pre 120 0 35 87 8 0 58 165 19 0 45 123 36
0-NFOA 0 26 32 102 22 28 43 142 5 24 21 65 41
45-NFOA 45 8 34 103 16 16 54 171 28 19 32 90 40
0-SBNRC 0 40 33 102 18 58 49 153 17 40 27 82 46
45-SBNRC 45 15 35 104 16 35 57 175 26 40 40 113 43
45-45 split 45 56 36 93 11 42 56 167 23 - - -  
90 Pre 90 0 35 94 11 0 59 180 27 - - -  
                         
Catch-up Trials


It is important to consider the impacts of early season N stress.  Can mid-season fertilizer N be applied (with NO preplant N) at rates sufficient to produce near maximum yields?  From these trials below, the answer is basically no.  Yes you can achieve near maximum yields, but at N rates that are simply not economical.  When early season N stress was present (0-N preplant), N applied topdress at Feekes 5 resulted in maximum or near maximum yields at 4 of 6 site-year combinations when compared to other treatments receiving both preplant and topdress N, but again, this was only achieved at very high rates.  Thus, early season N stress in wheat should be avoided.

 


Table 2. Profit earned for winter wheat OFIT trials, 2005 across sites, OK.

Trt

Preplant N

Topdress

Profit, $ ac-1

 

lb ac-1

lb ac-1

Altus

Covington

Hennessey

Lahoma

LCB

Perkins

Tipton

1

0

0

106

45

151

79

140

98

53

2

0

Flat

105

55

158

121

131

90

77

3

0

Flat

78

51

155

142

135

91

102

4

45

Flat

70

44

162

155

120

81

102

5

45

0

88

51

173

92

142

98

69

6

90

0

75

40

153

134

127

96

68

7

0

NFOA-CV

98

53

145

116

138

101

86

8

45

NFOA-CV

88

46

167

139

129

99

100

9

0

SBNRC

102

48

162

131

143

107

75

10

45

SBNRC

90

48

166

146

127

99

96

Publications and Fields Trials


  Extension Technology Publications

  Field Scale Variable Rate Trials, 2001, 2002, 2003, 2004