Transcript Nitrogen Management and its Influence on N Losses to

Developing an N Algorithm for
Northern Corn Belt Rainfed
Conditions:
Minnesota Experience
Jeff Vetsch and Gyles Randall
University of Minnesota
Southern Research and Outreach Center
http://sroc.coafes.umn.edu/
7/16/2015
Developing a MN N Algorithm:
Objective
• To develop an algorithm (nitrogen
recommendation) for sidedress
application that would:
– Maximize economic return to nitrogen
– Increase fertilizer use efficiency, and
– Incorporate some recently proposed and
refined N recommendations, based on a
regional database project.
7/16/2015
Minnesota - CC
140
0.05
0.10
0.15
0.20
Return to N, $/acre
120
100
80
60
40
20
0
0
7/16/2015
50
100
150
N Rate, lb N/acre
200
250
2004 remote sensing for N on corn
•
•
•
•
Previous crop: Corn removed for silage
Soil: Nicollet-Webster complex
N applied: 4/30 (PP), 6/28 (V8), 7/13 (V12)
Sensing dates: 6/23 (V7), 6/28 (V8), 7/7
(V10), 7/12 (V12), and 7/26 (R1).
7/16/2015
Corn grain yield and N uptake as affected by rate and
time of N application.
Total
Application Time
N Rate
PP
V8
V12
------------------- lb N/A ------------------0
0
0
0
40
40
0
0
80
80
0
0
120
120
0
0
160
160
0
0
200
200
0
0
80
40
40
0
120
40
80
0
160
40
120
0
80
40
0
40
120
40
0
80
160
40
0
120
Corn Grain
Yield N Uptake
bu/A
lb/A
92
40
146
68
176
92
177
99
190
117
188
117
164
88
190
113
190
114
166
84
185
105
186
109
Nebraska Approach
1.05
Relative SPAD
1
0.95
0.9
0.85
0.8
0.75
2
Y= 0.798150429+ (0.002112939 * Nrate)-(0.00000584568*(Nrate ))
0.7
0
50
100
150
Nrate (kg/ha)
7/16/2015
200
250
Corn grain yield vs relative chlorophyll
220
Corn grain yield, bu/acre
200
180
V8
V12
V10
R1
160
140
120
100
80
220
Corn grain yield, bu/acre
200
180
160
140
120
100
80
70
7/16/2015
80
90
Relative chlorophyll, %
100
70
80
90
Relative chlorophyll, %
100
Relative chlorophyll vs N rate at V8
100
Rel. Chlorophyll, %
95
90
85
80
75
70
0
7/16/2015
50
100
N Rate, lb/A
150
200
250
Relative chlorophyll vs N rate at V10
100
Rel. Chlorophyll, %
95
90
85
80
75
70
0
7/16/2015
50
100
N Rate, lb/A
150
200
250
Relative chlorophyll vs N rate at V12
100
Rel. Chlorophyll, %
95
90
85
80
75
70
0
7/16/2015
50
100
N Rate, lb/A
150
200
250
Relative chlorophyll vs N rate at R1
100
Rel. Chlorophyll, %
95
90
85
80
75
70
0
7/16/2015
50
100
N Rate, lb/A
150
200
250
Relative chlorophyll vs N rate at R1
100
Rel. Chlorophyll, %
95
90
85
80
75
70
0
7/16/2015
50
100
N Rate, lb/A
150
200
Predicted values based MN algorithm
N Rate
lb/A
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
V8
V10
V12
R1
-------------- relative chlorophyll, % -------------80.7
80.5
79.4
70.9
86.2
85.0
82.9
75.2
90.6
88.9
86.0
79.1
93.9
92.0
88.8
82.6
96.1
94.4
91.3
85.8
97.2
96.1
93.4
88.6
97.4
97.1
95.1
91.0
97.4
97.3
96.5
93.0
97.4
97.3
97.5
94.6
97.4
97.3
98.2
95.9
97.4
97.3
98.6
96.7
97.4
97.3
98.6
97.2
97.4
97.3
98.6
97.3
97.4
97.3
98.6
97.3
97.4
97.3
98.6
97.3
97.4
97.3
98.6
97.3
Sidedress N rates: MN algorithm
1201 – N rate credit2 = sidedress rate
1. Based on 2004 yield data, where a total of
120 lb N/A split applied yielded as well as
160 lb applied PP.
2. Based on relative chlorophyll content and
response curve at respective growth stage.
Application rates for the 2005 regional N project
Minnesota Treatments (V12 sensing, July 7)
Plot
#
104
204
303
411
105
208
313
412
1
Trt
#
11
11
11
11
12
12
12
12
PP
Chlorophyll MN Algorithm N Rate
N rate SPAD Rel.1
Credit
Applied
lb/A
%
------ lb N/A -----0
39.0 0.82
5
115
0
38.4 0.83
10
110
0
41.0 0.84
15
105
0
39.9 0.86
20
100
40
46.8 0.98
90
30
40
44.8 0.97
70
50
40
45.8 0.94
50
70
40
44.9 0.96
70
50
Relative calculated using 200 lb rate as reference (non limiting).
Growing season precipitation at Waseca in 2005
2.5
Precipitation, inch
2.0
1.5
1.0
0.5
0.0
5/2/05
5/16/05
5/30/05
6/13/05
6/27/05
7/11/05
7/25/05
8/8/05
MN “Norwegian” algorithm:
First-year experiences
• Advantages
– Simple intuitive / similar to Nebraska approach
– SPAD very good predictor of grain yield at V10-12
– Fits well with our new approach to N recommendations.
• Disadvantages / concerns
–
–
–
–
–
Algorithm based on ONE YEAR OF DATA (2004)
Need to adapt it to on-the-go sensing / application
Not sure if it will work for other soils / crop rotations
Still need a timely rain – cooperative weather
Need more out of range plots
• Is 120 lb N/A needed at sidedress or has yield potential already been
lost and cannot be attained, and how does growth stage affect recs.
THANKS
Jeff Vetsch
Assistant Scientist
Southern Research and Outreach Center
7/16/2015
[email protected]
http://sroc.coafes.umn.edu/
Precipitation
Month
May
June
July
August
Sept.
Total
7/16/2015
2004
2005
30-yr norm.
---------- inches ---------5.61
5.96
3.96
6.42
5.71
4.22
7.08
3.09
4.47
5.73
-4.58
6.92
-3.19
31.76
-20.42
Application rates for the 2005 regional N project
Minnesota treatments (est., V10 sensing, July 2)
Plot
#
104
204
303
411
105
208
313
412
1
Trt
#
11
11
11
11
12
12
12
12
PP
Chlorophyll MN Algorithm N Rate
N rate SPAD Rel.1 Predicted Applied
lb/A
%
------ lb N/A -----0
40.2 0.82
5
115
0
40.9 0.86
15
105
0
43.6 0.86
15
105
0
41.5 086
10
110
40
45.3 0.93
35
85
40
46.1 0.97
60
60
40
45.6 0.90
25
95
40
47.1 0.98
65
55
Relative calculated using 200 lb rate as reference (non limiting).
Application rates for the 2005 regional N project
Nebraska treatments (V10 sensing, July 2)
PP
Chlorophyll MN Algorithm N Rate
Plot Trt N rate SPAD Rel.1 Predicted Applied
#
#
lb/A
%
------ lb N/A -----103 7
0
45.8 0.94
90
75
214 7
0
46.5 0.98
140
25
308 7
0
46.8 0.93
77
88
409 7
0
47.0 0.97
130
35
113 8
40
45.2 0.93
80
85
202 8
40
47.0 0.99
180
0
312 8
40
47.4 0.94
90
75
410 8
40
46.7 0.97
120
45
52
1
Relative calculated using 200 lb rate as reference (non limiting).