Title

Fertilizing Hard Red Spring Wheat and Durum

(SF712, Revised Sept. 2022)
Summary

Nitrogen management is a key to successful wheat production. Recommendations include consideration of wheat yield and protein response to added N within three major state agri-climatology zones, and the use of wheat price and N cost in determining N rate. These recommendations are based on the concept that identifies an optimal N rate for greatest net income, not greatest yield.

Lead Author
Lead Author:
D.W. Franzen, NDSU Extension Soil Specialist
Availability
Availability:
Web only
Publication Sections
Fertilizing Hard Red Spring Wheat and Durum

Nitrogen recommendations for spring wheat and durum have been revised completely.

Nitrogen recommendations for spring wheat and durum have been revised completely.

Nitrogen (N) management is a key to successful wheat production. Recommendations include consideration of wheat yield and protein response to added N within three major regions, and the use of wheat price and N cost in determining N rate. These recommendations are based on the concept that identifies an optimal N rate for greatest net income, not greatest yield.

For the interactive North Dakota Spring Wheat and Durum Nitrogen Calculator, go to https://www.ag.ndsu.edu/temp/cnc/.

Nitrogen fertilizer costs are much higher and more volatile than in the past. Using site-specific technologies, growers have the ability to vary fertilizer rates on different areas of fields to manage their input risks. Government policies and regulations increasingly push growers toward more judicious use of plant nutrients.

These N-rate recommendations are the result of compiling archived N-rate studies from 1970 to 2004, and include data from a statewide N-rate research program conducted from 2005 to 2021. Studies contained yield and protein data, location, fertilizer N-rate and residual soil nitrate to 2 feet in depth. Approximately one-third of the data for the recommendations come from archived data and the other two-thirds were generated since 2005.

Wheat response to N fertilizer is closely linked to wheat protein concentration. Growers rely on higher protein markets to maintain their profitability. A protein of 14% or greater is necessary to avoid discounts at the point of sale. Sometimes premiums are available to growers for protein greater than 14%.

North Dakota data on analysis segregated into three regions: western, eastern and the Langdon region.

The western region is composed mostly of long-term no-till fields, with no-till continuous for at least six years in most fields, either pure no-till using only an opener for seed/fertilizer, or one-pass seeding, which only disturbs a couple inches at the soil surface at planting time. The western region is also typified by only sediment soils, a drier and warmer climate compared to conditions in the eastern region. The Langdon region segregates from the rest of the eastern region due to the shale pieces found commonly through the soil. The shale pieces contain high amounts of mineralizable ammonium, making the Langdon region soils essentially a slow-release natural fertilizer. The Langdon region requires less N for similar yields compared to the eastern region.

Higher-than-recommended N rates in the Langdon region results in pre-anthesis lodging. The amount of N required per bushel in the west was higher than in the east. Therefore, for the purposes of N recommendations for spring wheat and durum the state have been divided into three regions as shown in Figure 1.

Data from each zone were segregated and the relationships between wheat yield and available-N, and wheat protein and available-N, were established. Using the concept of “Return to N” from Sawyer and Nafziger (2005), the economic optimal N rate for wheat prices between between $3/bushel and $15/bushel and N costs from 20 cents/pound of N to $2/pound of N were developed using wheat price and protein discount or premium. The protein discount varies with grain elevator and the year.

The calculations used in developing these relationships used a 50 cent per point discount if protein were less than 14%, and a 50 cent per point premium from 14% to 15%, with no additional premium for greater protein than 15%. The gross N recommendations on the regional tables (Tables 1-9) contain the regional economic data for wheat yield and protein in the model.

Within each region, the optimal available N for three different productivities are defined as low, medium and high. The yield potential within each productivity category is defined for each region. This is done entirely for economic reasons, not for differences within region of yield/protein responses to N.

Productivity category definitions:

Langdon Region
Low = less than 40 bushels/acre
Medium = 41-60 bushels/acre
High = greater than 60 bushels/acre

Eastern Region
Low = less than 40 bushels/acre
Medium = 41-60 bushels/acre
High = greater than 60 bushels/acre

Western Region
Low = less than 30 bushels/acre
Medium = 31-50 bushels/acre
High = greater than 50 bushels/acre

Figure 1.
Figure 1. Regions used to segregate N-rate data and develop N recommendations.

Data from each zone were segregated and the relationships between wheat yield and available-N, and wheat protein and available-N, were established. Using the concept of “Return to N” from Sawyer and Nafziger (2005), the economic optimal N rate for wheat prices between $3/bushel and $10/bushel and N costs from 20 cents/pound of N and $1/pound of N were developed using wheat price and protein dock/premium. The protein dock varies with grain elevator and the year.

The figures used in developing these relationships used a 50 cent/point dockage if protein were less than 14 percent, and a 50 cent/point premium from 14 to 15 percent, with no additional premium for greater protein. The gross N recommendations on the regional tables (Tables 1-9) contain the regional economic data for wheat yield and protein in the model.

Within each region, the optimal available N for three different productivities are defined as low, medium and high. The yield potential within each productivity category is defined for each region. This is done entirely for economic reasons, not for differences within region of yield/protein responses to N.

To determine recommended N rate

  1. Find the region of the farm and look up the gross optimal available-N from the appropriate region/productivity table (Tables 1-9).
  2. Subtract the soil test nitrate-N from the 0- to 2-foot depth.
  3. Subtract any previous crop N credits (Table 10).
  4. Subtract or add no-till system N credits:
    – If field has been in no-till less than five consecutive years, add 20 pounds of N/acre.
    – If field has been in no-till greater than five consecutive years, subtract 50 pounds of N/acre.
  5. Organic matter credit for soils greater than 5 percent organic matter – Subtract 50 pounds of N/acre for each full percent organic matter above 5 percent.

From these optimum rates, the grower and adviser may choose to adjust plus/minus up to 30 pounds of N/acre. This adjustment may be used to anticipate a host of issues, including the following:

  • Subtract N for high protein varieties
  • Add N for lower protein varieties
  • Subtract N for areas with a history of early lodging
  • Add N for soils with denitrification issues
  • Add N for N application practices that are not ideal
  • For wheat after small grains, we assume about 2,000 pounds/acre of straw residue. For every 2,000 pounds/acre of straw greater than this, add 30 pounds of N/acre.

As N costs increase and wheat price decreases, optimum N will not be highest yield or protein. However, from our database, these rates will provide the greatest net income.

Table 1a. Langdon region, conventional tillage low productivity (less than 40 bushels per acre), $0.20 - $1.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

Nitrogen Recommended, pounds per acre

3

112

100

90

52

0

0

0

0

0

4

124

100

100

87

62

37

0

0

0

5

132

116

100

100

85

66

47

42

0

6

137

123

110

100

99

84

69

52

47

7

141

129

117

106

100

97

84

71

57

8

143

133

123

113

103

100

94

83

72

9

145

136

127

118

109

100

100

93

83

10

145

139

131

123

115

107

100

100

91

11

145

141

134

126

119

112

104

100

98

12

145

145

134

127

125

114

107

100

98

13

145

145

136

130

125

117

111

105

98

14

145

145

138

132

127

121

115

109

103

15

145

145

140

134

129

123

118

112

104

Table 1b. Langdon region, conventional tillage low productivity (less than 40 bushels per acre), $1.10 - $2.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

1.90

2.00

Nitrogen Recommended, pounds per acre

3

0

0

0

0

0

0

0

0

0

0

4

0

0

0

0

0

0

0

0

0

0

5

0

0

0

0

0

0

0

0

0

0

6

30

14

0

0

0

0

0

0

0

0

7

47

41

22

0

0

0

0

0

0

0

8

60

47

47

16

0

0

0

0

0

0

9

73

63

52

47

40

17

13

0

0

0

10

83

74

65

56

47

35

34

23

11

0

11

90

82

74

66

58

50

47

39

30

20

12

95

89

80

73

65

58

50

45

42

33

13

98

93

87

82

73

66

60

53

47

46

14

98

98

92

86

80

74

67

61

55

48

15

101

98

97

91

86

80

74

68

62

56

Table 2a. Langdon region, conventional tillage medium productivity (41-60 bushels per acre), $0.20 - $1.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

Nitrogen Recommended, pounds per acre

3

130

125

120

115

110

100

80

50

50

4

135

130

125

120

115

100

90

80

70

5

140

135

130

125

120

115

100

90

80

6

145

140

135

130

120

115

105

95

85

7

150

145

140

135

125

120

110

100

95

8

155

150

145

140

130

125

115

105

100

9

160

155

150

145

135

130

120

110

105

10

165

160

155

150

145

135

125

120

110

11

175

170

165

155

150

140

130

125

115

12

178

171

165

157

150

143

136

128

121

13

178

172

165

159

152

146

139

132

126

14

178

172

166

160

154

148

142

136

130

15

178

173

167

162

156

150

145

139

133

Table 2b. Langdon region, conventional tillage medium productivity (41-60 bushels per acre), $1.10 - $2.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

1.90

2.00

Nitrogen Recommended, pounds per acre

3

30

20

15

10

0

0

0

0

0

0

4

50

40

30

25

0

0

0

0

0

0

5

60

50

40

35

10

0

0

0

0

0

6

65

60

50

45

25

10

0

0

0

0

7

70

70

60

55

35

30

20

10

0

0

8

80

80

70

65

45

40

30

20

15

0

9

90

90

80

75

55

50

40

30

25

10

10

100

95

85

80

65

60

50

40

35

20

11

110

100

90

85

75

65

60

50

40

30

12

114

107

99

92

84

77

69

62

54

46

13

119

112

106

99

92

86

78

72

65

58

14

124

118

111

105

99

93

86

80

74

67

15

128

122

116

110

104

99

93

87

81

75

Table 3a. Langdon region, conventional tillage, high productivity (greater than 60 bushels per acre), $0.20 - $1.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

Nitrogen Recommended, pounds per acre

3

167

165

163

160

155

148

135

120

101

4

172

168

165

162

156

150

141

131

121

5

177

170

168

164

157

151

144

137

130

6

178

172

170

168

158

152

146

140

134

7

178

174

172

170

160

152

147

143

139

8

178

175

173

171

161

152

147

144

142

9

178

176

174

172

162

154

149

146

142

10

178

176

174

172

162

154

149

146

142

11

178

176

174

172

162

154

149

146

142

12

178

176

174

172

162

154

149

146

142

13

178

176

174

172

162

154

149

146

142

14

178

176

174

172

162

154

149

146

142

15

178

176

174

172

162

154

149

146

142

Table 3b. Langdon region, conventional tillage, high productivity (greater than 60 bushels per acre), $1.10 - $2.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

1.90

2.00

Nitrogen Recommended, pounds per acre

3

77

35

20

0

0

0

0

0

0

0

4

110

98

84

50

30

20

0

0

0

0

5

122

114

105

96

86

76

65

52

30

10

6

128

122

116

109

102

95

88

80

72

50

7

133

128

121

117

112

106

101

95

89

83

8

136

131

127

123

118

114

109

104

99

94

9

138

133

131

127

123

119

115

111

107

103

10

138

134

133

130

126

123

119

116

112

109

11

138

134

133

130

129

126

123

120

117

113

12

138

134

133

130

129

127

126

123

120

117

13

138

134

133

130

129

127

126

126

123

121

14

138

134

133

130

129

127

126

126

125

123

15

138

134

133

130

129

127

126

126

125

124

 

Table 4a. Eastern region, conventional tillage, low productivity (less than 40 bushels per acre), $0.20 - $1.00 N cost/lb.

Wheat
$ per bu

Nitrogen Recommended, pounds per acre

3

142

130

120

82

0

0

0

0

0

4

154

130

130

117

92

77

39

0

0

5

162

146

130

130

115

96

77

72

34

6

167

153

140

130

129

114

99

82

77

7

171

159

147

136

130

127

114

101

87

8

173

163

153

143

133

130

124

113

102

9

175

166

157

148

139

130

130

123

113

10

175

169

161

153

145

137

130

130

121

11

175

171

164

156

149

142

134

130

128

12

175

175

164

157

155

144

137

130

128

13

175

175

166

160

155

147

141

135

128

14

175

175

168

162

156

151

145

139

133

15

175

175

170

164

159

153

148

142

137

Table 4b. Eastern region, conventional tillage, low productivity (less than 40 bushels per acre), $1.10 - $2.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

1.90

2.00

Nitrogen Recommended, pounds per acre

3

0

0

0

0

0

0

0

0

0

0

4

0

0

0

0

0

0

0

0

0

0

5

0

0

0

0

0

0

0

0

0

0

6

60

44

0

0

0

0

0

0

0

0

7

77

71

52

30

0

0

0

0

0

0

8

90

77

77

46

29

0

0

0

0

0

9

103

93

82

77

70

57

43

29

13

0

10

113

104

95

86

77

75

64

53

41

28

11

120

112

104

96

88

80

77

69

60

50

12

125

119

110

103

95

88

80

75

72

63

13

128

123

117

112

103

96

90

83

77

76

14

128

128

122

116

112

104

97

91

85

78

15

131

128

127

121

116

110

104

98

92

86

Table 5a. Eastern region, conventional tillage, medium productivity (41-60 bushels per acre), $0.20 - $1.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

Nitrogen Recommended, pounds per acre

3

178

150

120

117

100

42

0

0

0

4

182

161

141

118

118

103

72

33

0

5

183

167

150

133

120

118

103

82

57

6

184

171

157

143

128

118

118

105

86

7

185

173

162

150

137

125

118

118

118

8

186

176

165

155

144

133

122

118

118

9

186

177

168

159

149

140

130

121

118

10

187

178

170

162

155

145

136

130

119

11

187

179

172

164

158

149

141

134

126

12

187

180

173

166

160

153

146

138

131

13

187

181

175

168

162

155

149

143

136

14

188

182

176

170

164

158

152

146

140

15

188

182

177

171

166

160

154

149

143

Table 5b. Eastern region, conventional tillage, medium productivity (41-60 bushels per acre), $1.10 - $2.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

1.90

2.00

Nitrogen Recommended, pounds per acre

3

0

0

0

0

0

0

0

0

0

0

4

0

0

0

0

0

0

0

0

0

0

5

29

0

0

0

0

0

0

0

0

0

6

69

49

28

0

0

0

0

0

0

0

7

91

76

60

44

27

8

0

0

0

0

8

105

93

81

68

54

40

26

11

0

0

9

118

118

95

84

73

62

50

38

26

13

10

118

118

105

96

87

77

68

57

47

36

11

118

118

118

106

97

89

80

71

61

53

12

124

118

118

118

106

98

90

83

75

67

13

129

123

122

118

113

106

99

92

85

77

14

135

128

122

118

118

118

106

99

93

86

15

138

132

126

121

118

118

118

106

100

94

Table 6. Eastern region conventional tillage, high productivity (greater than 60 bushels per acre), $0.20 - $1.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

Nitrogen Recommended, pounds per acre

3

218

202

185

167

148

147

145

129

109

4

227

213

199

184

169

154

147

147

137

5

233

221

209

196

184

171

158

147

147

6

237

227

216

205

195

184

173

161

150

7

241

231

222

212

203

193

184

174

164

8

244

235

227

218

210

205

193

183

175

9

246

238

231

223

215

207

199

191

183

10

248

241

234

227

220

212

205

198

191

11

250

243

237

230

223

217

210

203

197

12

250

245

239

233

227

221

214

208

201

13

250

247

241

235

230

224

218

212

206

14

250

247

243

237

232

227

221

216

210

15

250

250

245

239

235

229

224

219

214

Table 6b. Eastern region conventional tillage, high productivity (greater than 60 bushels per acre), $1.20 - $2.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

1.90

2.00

Nitrogen Recommended, pounds per acre

3

81

50

35

20

10

0

0

0

0

0

4

123

106

85

65

40

30

15

0

0

0

5

143

131

118

104

86

63

40

30

20

10

6

147

147

137

127

115

102

88

70

43

30

7

153

147

147

142

133

123

112

101

88

74

8

165

156

147

147

146

137

129

120

110

100

9

174

167

159

149

147

147

141

133

125

117

10

184

176

168

161

153

147

147

144

137

130

11

190

183

176

169

162

155

148

147

147

141

12

196

189

183

177

170

164

157

151

147

147

13

201

195

194

183

176

171

165

159

153

147

14

205

199

194

188

183

177

172

166

160

155

15

209

204

198

193

188

183

178

172

167

162

Table 7a. Western region, conventional tillage, low productivity (less than 30 bushels per acre), $0.20 - $1.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

Nitrogen Recommended, pounds per acre

3

99

95

93

76

59

55

30

0

4

102

97

95

85

68

60

54

42

5

105

99

97

90

71

64

60

52

6

108

103

98

93

78

68

66

60

7

111

107

100

96

86

74

72

65

8

114

110

103

99

90

82

77

70

9

117

112

106

100

93

86

82

77

10

120

114

109

103

96

92

88

84

11

120

116

110

105

100

95

93

90

12

120

118

112

107

102

98

96

94

13

120

120

114

108

104

101

98

96

14

120

120

120

111

107

104

100

97

15

120

120

120

120

112

108

101

98

Table 7b. Western region, conventional tillage, low productivity (less than 30 bushels per acre), $1.10 - $2.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

1.90

2.00

Nitrogen Recommended, pounds per acre

3

0

0

0

0

0

0

0

0

0

0

4

0

0

0

0

0

0

0

0

0

0

5

0

0

0

0

0

0

0

0

0

0

6

50

45

28

9

0

0

0

0

0

0

7

58

52

51

39

26

11

0

0

0

0

8

66

57

55

45

35

25

13

0

0

0

9

73

64

60

52

46

35

41

13

11

10

10

77

68

62

59

54

45

44

23

20

15

11

84

79

74

68

63

56

47

42

38

20

12

88

83

79

74

69

64

59

48

45

40

13

92

86

83

78

73

69

65

60

56

50

14

95

90

86

82

78

74

70

65

61

58

15

96

93

89

85

82

78

74

70

66

62

Table 8a. Western region, conventional tillage medium productivity (31-50 bushels per acre), $0.20 - $1.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

Nitrogen Recommended, pounds per acre

3

148

139

139

138

121

102

102

101

60

4

162

139

139

139

139

138

115

102

102

5

172

153

139

139

139

138

117

102

102

6

178

162

146

139

139

138

134

102

102

7

182

169

155

141

139

139

138

113

113

8

186

174

162

149

139

139

139

127

127

9

188

178

167

156

145

139

139

136

136

10

190

181

171

162

151

142

139

137

137

11

192

183

174

165

157

148

139

139

139

12

194

186

177

169

161

153

145

139

139

13

194

187

180

172

165

157

150

142

139

14

196

189

183

176

168

162

154

147

140

15

196

190

184

177

171

164

158

151

145

Table 8b. Western region, conventional tillage medium productivity (31-50 bushels per acre), $1.10 - $2.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

1.90

2.00

Nitrogen Recommended, pounds per acre

3

50

30

15

0

0

0

0

0

0

0

4

101

80

60

40

20

0

0

0

0

0

5

101

80

65

55

45

30

10

0

0

0

6

102

101

90

70

50

40

30

20

0

0

7

102

102

101

96

65

50

40

30

20

0

8

113

102

102

101

98

76

48

35

25

15

9

124

113

102

102

101

100

83

63

38

20

10

135

124

112

102

102

101

101

87

71

53

11

138

132

122

112

102

102

101

101

90

77

12

139

138

130

121

112

103

102

101

101

92

13

139

138

138

129

121

112

103

102

101

102

14

139

139

138

135

127

119

112

105

102

102

15

139

139

139

138

133

126

119

111

104

102

Table 9a. Western region conventional tillage high productivity (greater than 50 bushels per acre), $0.20 - $1.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

Nitrogen Recommended, pounds per acre

3

164

157

127

95

61

25

0

0

0

4

164

164

147

125

101

77

52

26

0

5

172

164

159

141

123

104

85

66

46

6

178

164

164

152

137

122

106

91

75

7

182

169

165

158

147

134

122

108

95

8

185

174

166

164

154

143

132

120

109

9

187

177

168

164

160

155

140

130

120

10

189

180

170

164

164

156

147

138

129

11

190

181

175

167

164

160

152

144

136

12

192

184

177

170

164

164

157

149

142

13

193

186

180

172

166

164

160

154

147

14

194

187

181

175

169

164

164

157

151

15

195

189

183

177

171

164

164

161

155

Table 9b. Western region conventional tillage high productivity (greater than 50 bushels per acre), $1.10 - $2.00 N cost/lb.

Wheat
$ per bu

N cost $ per pound

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

1.90

2.00

Nitrogen Recommended, pounds per acre

3

0

0

0

0

0

0

0

0

0

0

4

0

0

0

0

0

0

0

0

0

0

5

26

0

0

0

0

0

0

0

0

0

6

59

43

26

0

0

0

0

0

0

0

7

81

68

54

27

0

0

0

0

0

0

8

98

86

74

63

51

39

27

0

0

0

9

110

100

90

79

69

59

48

38

27

0

10

120

111

102

92

83

74

65

55

46

37

11

128

120

111

103

95

86

78

70

61

53

12

134

127

119

112

103

97

89

81

74

66

13

140

133

128

119

112

105

98

91

84

77

14

145

138

133

125

119

113

106

100

93

87

15

149

143

137

131

125

119

113

107

101

95

Table 10. Previous crop N credits

Previous crop

Credit

Soybean

40 lb N/acre

Edible bean

40 lb N/acre

Pea and lentil

40 lb N/acre

Chickpea

40 lb N/acre

Sweet clover that was harvested

40 lb N/acre

Alfalfa that was harvested and unharvested sweet clover:

 

>5 plants/sq ft

150 lb N/acre

3-4 plants/sq ft

100 lb N/acre

1-2 plants/sq ft

50 lb N/acre

<1 plant /sq ft

0 lb N/acre

Sugar beet

 

Yellow leaves

0 lb N/acre

Yellow/green leaves

30 lb N/acre

Dark green leaves

80 lb N/acre

Second-year N Credits

Half of credit given for the first year for sweet clover and alfalfa; none for other crops.

Nitrogen Application

Where acceptable, fall application of ammonia is a preferred method of N application. Fall application is acceptable on loam soils or heavier in areas not prone to spring flooding after snowmelt. Fall application of ammonia should not begin before Oct. 1, and then only after soil temperatures measured at the 4-inch depth fall to 50 degrees Fahrenheit between 8 a.m. and 10 a.m. Banded urea may be applied a week after this date, and broadcast and incorporated urea should wait two weeks after the ammonia-safe date.

For greatest efficiency, urea should be applied below the soil surface. In no-till management, this can be accomplished with seeding tools that spread the urea at or near seed-depth if rate is sufficiently low, or in a band with seed to fertilizer separation of at least 1 inch. If urea is applied to the soil surface, it should be applied using a urease inhibitor. The urease inhibitor shown most effective is NBPT, which is marketed under a number of trade names. The proper NBPT rate is 1.78 pounds active ingredient per ton of urea (3 quarts per ton, 26.7% a.i., density 8.9 pounds per gallon). The NBPT at the proper rate almost completely renders soil urease inactive for about 10 days, during which time rainfall usually moves the urea into the soil, preventing ammonia volatilization. For additional information about urease inhibitors, see Nitrogen Extenders and Additives for Field Crops at https://www.ndsu.edu/agriculture/extension/publications/nitrogen-extenders-and-additives-field-crops.

Liquid N sources, including UAN/ 28-0-0, are also best applied below the surface. If spring conditions prevent below-surface application, banding the 28% on the surface may delay volatilization several days, compared with broadcast application.

Protein Enhancement

North Dakota research has shown that the best chance of protein enhancement of spring wheat and durum is accomplished by waiting until the end of flowering (post-anthesis) and broadcasting 10 gallons per acre of UAN/28-0-0 (30 pounds of N per acre) mixed with 10 gallons per acre of water over the wheat in the cool of the day. Some leaf burning will result. The use of an equivalent N rate of urea solution also has been effective, and if the urea is low in biuret content, the addition of water dilution is not necessary and leaf burn is reduced. For research studies on protein enhancement in spring wheat, see https://www.ndsu.edu/agriculture/ag-hub/publications/post-anthesis-n-application-studies-north-dakota-region-and-elsewhere

The addition of some herbicides, fungicides and insecticides may increase the intensity of leaf burn and limit the efficacy of the pesticide application. About a 0.5% grain protein increase has been achieved using this method. The use of low rates of slow-release N products before or after anthesis has not been shown to increase grain protein effectively. For more information regarding the use of low rates of specialty N products for protein enhancement see https://www.ndsu.edu/agriculture/ag-hub/publications/studies-slow-release-liquid-fertilizers-applied-low-rates-foliar-application

Phosphate

The phosphate (P) recommendation in North Dakota currently is based on the Olsen P soil test. The broadcast recommendations appear in Table 11.

If the fertilizer is applied as a band, rates in Table 11 can be reduced by one-third. Reducing rates in low-testing soils will result in soil test levels that do not increase through time.

Reducing rates is suggested when P costs are high. At P costs of 30 cents/pound of P2O5 and less, the profitability of applying P to wheat is positive at soil test values indicated in Table 11. However, when 11-52-0 sells for more than $350/ton, using more than a minimum amount of P as a starter becomes unprofitable at a wheat price of $6/bushel. As wheat prices increase above $6/bushel, the grower can apply P at higher cost profitably (Figure 2).

Wheat benefits greatly from banded fertilizer placement near the row or in the row at seeding, provided that rates are moderate. Yield increases of several bushels per acre due to banded P are common in P banding vs. broadcast studies in wheat.

The rate of fertilizer that can be applied safely with wheat seed is more dependent on the N content of the fertilizer than the P content. Maximum N fertilizer rates that can be used with the seed are provided in Tables 12 and 13.

Table 11. Broadcast fertilizer phosphate recommendations for North Dakota for spring wheat and durum based on soil test (Olsen sodium bicarbonate and yield potential.
Soil Test Phosphorous, ppm
VL 0-3 L 4-7 M 8-11 H 12-15 VH 16+
Pounds P2O5/acre
90 60 35 20

15*

* Wheat seeding always should include a small amount of starter fertilizer in a band regardless of soil test.  It starter fertilizer banding is not used, rates in H and VH categories should be zero.

Reducing rates is suggested most when P costs are relatively high. At 30 cents/pound of P2O5 and below, the profitability of applying P to wheat is positive at soil test levels indicated in Table 11. However, when 11-52-0 sells for more than $350/ton, using more than a minimum amount of P as a starter becomes unprofitable at a wheat price of $6/bushel. As wheat prices increase above $6/bushel, the grower can apply P at higher cost profitably (Figure 4).

Figure 2. Profitability of using P for $6/bushel wheat at 30 cent/pound of P2O5, 50 cent/pound P2O5, and $1/pound P2O5. From Halvorson (1978)
Figure 4. Profitability of using P for $6/bushel wheat at 30 cent/pound of P2O5, 50 cent/pound P2O5, and $1/pound P2O5. From Halvorson (1978).

Wheat benefits greatly from banded fertilizer placement near the row or in the row at seeding, provided that rates are moderate. Yield increases of several to many bushels are common in P banding vs. broadcast studies in wheat.

The rate of fertilizer that can be applied safely with wheat seed is more dependent on the N content of the fertilizer than the P content. Maximum N fertilizer rates that can be used with the seed are provided in Tables 12 and 13.

Table 12. Maximum N fertilizer rates with wheat seed at planting based on row spacing, planter opener type and seedbed utilization (From Franzen, 2015a). SU = seedbed utilization.

Planter
Opener
tType

Seed
Spread

inches

Row spacing, inches

6

 

7.5

 

10

 

12

SU

lb N/acre

 

SU

lb N/acre

 

SU

lb N/acre

 

SU

lb N/acre

Double-disc

1

17%

20-30

 

13%

19-28

 

10%

17-23

 

8%

15-20

Hoe

2

33%

32-44

 

27%

27-38

 

20%

23-31

 

17%

20-27

 

3

50%

44-58

 

40%

37-48

 

30%

30-40

 

25%

26-34

Air-Seeder

4

66%

56-72

 

53%

46-58

 

40%

37-48

 

33%

32-42

 

5

83%

68-86

 

68%

56-68

 

50%

44-57

 

44%

38-49

 

6

100%

80-100

 

80%

66-79

 

60%

51-55

 

50%

44-56

 

7

     

94%

76-90

 

70%

58-74

 

58%

50-64

 

8

           

80%

66-83

 

67%

56-71

 

9

           

90%

73-92

 

75%

62-78

 

10

           

100%

80-100

 

83%

68-86

 

11

                 

92%

74-93

 

12

                 

100%

80-100

Table 13. Maximum N fertilizer rates with wheat at planting based on soil texture and seedbed utilization. From Franzen, 2015a.

Soil texture

   

Percent seedbed utilization

Particle size

10-20
Double-disc
1 inch

30-50
Hoe
2-3 inches

60-100
Air seeder
4-12 inches

Sand

Silt

Clay

 

———— Percent ————

 

———————— Pounds N per acre ———————

Loamy sand

80

10

10

 

5

10-20

25-40

Sandy loam

60

35

15

 

10

15-25

30-45

Sandy clay loam

55

15

30

 

15

20-30

35-50

Loam

40

40

20

 

20

25-35

40-55

Silt loam

20

65

15

 

25

30-40

45-60

Silty clay loam

10

55

35

 

30

35-45

50-70

Clay loam

30

30

40

 

35

40-50

55-80

Clay

20

20

60

 

40

45-55

60-100

Potassium

The potassium (K) recommendations have changed. Finding responses to K is difficult when soil test K levels are greater than 100 parts per million (ppm). Nearly all of the higher K responses are related to a chloride response.

Most soils in North Dakota have high enough potassium (K) levels to support excellent wheat production. Exceptions might be sandier soils or soils with a history of many years of continuous soybean.

Current K fertilizer recommendations are based on a soil test critical level of 100 ppm. The recommendation in higher-testing soils is provided to replace K that the crop will remove and to provide chloride if necessary. If chloride (Cl) values are adequate and other crops in the rotation regularly receive K fertilizer, then KCl application when K and Cl are in the high range category are not necessary.

Potassium Recommendations

Potassium Recommendations

Soils with smectite-to-illite clay chemistry ratio of 3.5 or less (Figure 3)

• Soil test K > 150 ppm, no additional K required.

• KCl (0-0-60-50Cl) may be applied if soil Cl levels are less than 40 pounds of Cl in a 2-foot depth.

• Soil test K 150 ppm or less, apply 50 pounds/acre KCl (25 pounds/acre K2O)

Soils with smectite-to-illite clay chemistry ratio more than 3.5 (Figure 3)

• Soil test K > 100 ppm, no additional K required.

• KCl (0-0-60-50Cl) may be applied if soil Cl levels are less than 40 pounds Cl/2-foot depth.

• Soil test K 100 ppm or less, apply 50 pounds/acre KCl (25 pounds/acre K2O)

Sulfur

Sulfur (S) has become more important than K or Cl in North Dakota as the third major crop nutrient. Environmental regulations on fossil fuel emissions have put stringent restrictions on sulfur emissions in recent years. Industry response to regulation has resulted in less S received in North Dakota fields from precipitation (Franzen 2015b).

The S soil test is a very poor predictor of soil S status. Sulfur deficiency has become so prevalent in small grains and corn that for spring wheat/durum, a base application of 10 pounds of S per acre would be prudent, particularly if the fall, winter or early spring before seeding has received normal to above normal precipitation. Soils with sandy loam or coarser textures and less than 3% organic matter on higher landscape positions are most at risk, but all soils are at risk in wetter seasons.

Sulfur fertilizer application is a spring operation because sulfate leaches easily beyond the rooting zone. The spring fertilizer application should consist of a soluble sulfur fertilizer. Ammonium sulfate at rates of about 10 pounds of S per acre or gypsum (calcium sulfate) at 20 pounds of S per acre would be excellent sources of sulfur. Ammonium thiosulfate (ATS) is a liquid formulation of S that is highly plant-available. However, ATS should not be applied with the seed at planting, nor should it be broadcast over wheat after emergence.

Elemental S, even premium bentonite-blended forms, are not nearly as useful in correcting a deficiency as sulfate/thiosulfate fertilizers. Composite blended granules of phosphate fertilizers that include sulfur could be used, but rates need to be high enough to supply the 10 pounds of S per acre needed as the ammonium sulfate portion of the fertilizer, or the application should be supplemented with a sulfate containing fertilizer.

Copper

Increases in yield and decreases in fusarium head blight (scab) have been documented in North Dakota (Franzen et al., 2008) with copper application. The responses to copper were seen mostly on low-organic matter, sandy soils. However, only about 15% of sites that fit these criteria in the study responded.

Predicting whether wheat grown on these soils would respond to copper is difficult. Copper application is a site-specific nutrient at best. Applying it on loam or heavier soils, or in soils between 3% and 8% organic matter, provides no benefit. An application of copper sulfate at a rate of 5 pounds of Cu/acre will last many years.

Chloride

Chloride responses are well-documented for spring wheat and durum. Studies in the state and the region show that wheat tends to respond positively to chloride about half the time, with yield increases of 2 to 5 bushels/acre. Studies in consecutive years investigating varietal responses to chloride provided inconsistent results.

Yield increases from Cl arise from increased resistance to certain root and leaf diseases and an increase in kernel size. The critical soil test value of Cl is 40 pounds per acre in the surface 2-feet of soil. If the soil test is less than 40 pounds of Cl per acre, fertilizing with 5 to 10 pounds of Cl per acre with or near the seed at planting should sufficiently supply the crop for the year.

Other Nutrients

No evidence exists that supplemental zinc, iron, manganese or boron are required for spring wheat or durum wheat in North Dakota. Although numerous reports have been made in the U.S. and around the world of these nutrients being required as fertilizer, our soils apparently supply enough of these nutrients and our wheat is adapted to these soils; therefore, these nutrients do not need to be supplied artificially.

Acknowledgments

Thanks to my collaborative researchers Gregory Endres, Carrington Research Extension Center; Roger Ashley and Glenn Martin, Dickinson Research Extension Center; John Lukach, retired, Langdon Research Extension Center; James Staricka, Williston Research Extension Center; and Kent McKay, formerly Extension area specialist with the North Central Research Extension Center. Funding for studies that contributed data to these recommendations came from North Dakota SBARE-Wheat Committee, North Dakota Wheat Commission, US-NSF grant number PFI-1114363, and USDA-ARS project No. 58-6064-8-023.

References

Bauer, A. 1970. Nitrogen uptake by irrigated wheat under varying fertilizer nitrogen application rates. p. 95-99. In. NDAA 22nd Annual Fertilizer Conference. Soil Management for Crop Production and Environmental Protection Short Course. Dec. 3-4, 1970, Fargo, N.D. North Dakota Plant Food Association and NDSU Extension Service.

Bauer, A. 1971. Fertilizer nitrogen effects on spring wheat varieties. p. 8-21. In 1971 North Dakota Crop Production Guide. NDSU Extension Service, Fargo, N.D.

Dahnke, W.C. 1981. Department memo. Jan. 29, 1981.

Etchevers, J.D. 1970. Effect of CCC and nitrogen on two cereals. M.S. thesis, NDSU.

Franzen, D.W., M. McMullen and D.S. Mossett. 2008. Spring wheat and durum yield and disease responses to copper fertilization of mineral soils. Agronomy Journal 100:371-375.

Franzen, D.W. 2015a. Fertilizer application with small grain seed at planting. NDSU Extension publication EB62 (revised).

Franzen, D.W. 2015b. Sulfur sources, chemistry, extent of deficiencies, and application considerations in the North Central Region of the USA. p. 22-43. In Proceedings of the North Central Extension-Industry Soil Fertility Conference, Nov. 4-52015. Des Moines, Iowa. IPNI, Peachtree Corners, Ga.

Goos, R.J., B. Johnson and F. Sobolik. 1982. Fertilizer studies on recropped small grain in western N.D., 1981. p. 200-202. 1982 North Dakota Crop Production Guide. NDSU Extension Service, Fargo, N.D.

Goos, R.J., B.E. Johnson, E.J. Deibert and F.J. Sobolik. 1981. The effects of N rate, N source, P, and K on the yield and protein content of spring wheat. p. 191-194. In 1981 North Dakota Crop Production Guide. NDSU Extension Service, Fargo, N.D.

Goos, R.J. 1983. Small grain soil fertility investigations, 1979-1983. p. 27-30. In North Dakota Farm Research. Vol. 4, No. 1. North Dakota State University Agricultural Experiment Station, Fargo, N.D.

Halvorson, A.D. 1986. Phosphorus management for MEWY and quality. 12 p. Presented at Hands-On Workshop for Implementing Maximum Economic Wheat Yield Systems. July 8-11, 1986. Bismarck, N.D.

Sawyer, J., and E. Nafziger. 2005. Regional approach to making nitrogen fertilizer rate decisions for corn. p. 16-24. In Proceedings of the North Central Extension-Industry Soil Fertility Conference, Nov. 16-17, 2005, Des Moines, Iwa. Potash & Phosphat Institute, Brookings, S.D.

Schneider, R.P. 1980. N Sources and N-Serve in North Dakota spring wheat production. p. 216-221. In 1980 North Dakota Crop Production Guide. NDSU Extension Service, Fargo, N.D.

Sobolik, F. Nitrogen use on fallow and re-cropped land in northwest North Dakota. p. 243-244. In 1977 North Dakota Crop Production Guide. NDSU Extension Service, Fargo, N.D.

Vanden Heuvel, R.M. 1980. Effect of time of residue incorporation, time of N application, N rate and N source on HRS wheat (Triticum aestivum L.). NDSU M.S. thesis.