Results from Regional Algorithm Evaluation Study

1
Results from Regional Algorithm Evaluation Study

• Robert Mullen and Newell Kitchen
• August 6, 2009

2
Overview

• Discussion on how work has been done
• SAS discussion
• Models currently used
• Individual site data
• Brief illustration of individual sites
• Algorithm performance across all sites
• Correlation information
• Other analysis performed

3
Analytical Approach

• Everything is SAS based
• Very intricate code that allows us to conduct all
  the analysis with actually touching the data
• SAS parameters
• Low stands are thrown out of the data set
  (lt19,000 plants/acre)
• Inverse simple ratio (ISR) is computed from NDVI
• For some reason, certain sites have disagreement
  between NDVI and ISR

4
Analytical Approach

• Currently using a quadratic plateau model to
  identify optimum N rates for each location
• Each algorithm is hard coded so that N
  recommendations can easily be compared to optimum
  N rates for each location

5
By-Site Data
Y -0.0055x2 1.18x 71.52 Joint 107 Plat
135
6
By-Site Data
Y -0.0039x2 1.08x 102.49 Joint 137 Plat
177
7
By-Site Data
Y -0.0031x2 0.82x 113.04 Joint 133 Plat
168
8
By-Site Data
Y -0.012x2 1.80x 140.98 Joint 75 Plat
209
9
By-Site Data
Y -0.0097x2 1.79x 137.32 Joint 92 Plat
220
10
By-Site Data
Y -0.020x2 1.10x 216.75 Joint 27 Plat
232
11
By-Site Data
Y -0.020x2 0.14x 141.25 Joint 0 Plat 141
12
By-Site Data
Y -0.0021x2 0.92x 72.16 Joint 180 Plat
168
13
By-Site Data
Y -0.00x2 0.29x 143.97 Joint 180 Plat
196
14
By-Site Data
Y -0.0027x2 1.12x 82.21 Joint 180 Plat
195
15
By-Site Data
Y -0.0021x2 0.47x 202.90 Joint 109 Plat
228
16
By-Site Data
Y -0.020x2 1.17x 79.15 Joint 29 Plat 96
17
By-Site Data
Y -0.020x2 0.83x 135.80 Joint 21 Plat
145
18
By-Site Data
Y -0.020x2 0.80x 199.87 Joint 20 Plat
208
19
By-Site Data
Y -0.0035x2 1.04x 132.45 Joint 147 Plat
209
20
By-Site Data
Y -0.0048x2 1.12x 156.95 Joint 117 Plat
222
21
By-Site Data
Y -0.020x2 0.74x 100.23 Joint 18 Plat
107
22
By-Site Data
Y -0.0017x2 0.66x 118.93 Joint 180 Plat
183
23
By-Site Data
Y -0.0032x2 0.52x 143.00 Joint 81 Plat
164
24
By-Site Data
Y -0.020x2 1.01x 194.76 Joint 0 Plat 195
25
By-Site Data
Y -0.0037x2 1.01x 115.19 Joint 137 Plat
185
26
By-Site Data
Y -0.020x2 0.97x 150.40 Joint 24 Plat
162
27
By-Site Data
Y -0.020x2 - 0.16x 147.53 Joint 0 Plat
148
28
By-Site Data
Y -0.0034x2 0.66x 110.87 Joint 97 Plat
143
29
By-Site Data
Y -0.0043x2 1.45x 68.74 Joint 171 Plat
193
30
By-Site Data
Y -0.00078x2 0.78x 69.29 Joint 180 Plat
184
31
By-Site Data
Y -0.0011x2 0.35x 110.53 Joint 166 Plat
140
32
By-Site Data
Y -0.0062x2 1.14x 127.34 Joint 93 Plat
180
33
By-Site Data
Y -0.0021x2 0.63x 117.28 Joint 154 Plat
166
34
By-Site Data
Y -0.00046x2 0.48x 42.11 Joint 180 Plat
114
35
Algorithm Performance
36
Algorithm Performance
37
Algorithm Performance
38
Algorithm Performance
39
Algorithm Performance
40
Algorithm Performance
41
Algorithm Performance
42
Algorithm Performance
43
Algorithm Performance
44
Algorithm Performance
45
Algorithm Performance
46
Algorithm Performance
47
Algorithm Performance
48
Algorithm Performance
49
Additional Analysis
Y -0.014x2 3.01x 5.81 r2 0.75 Joint
107 Plat 167
50
Thanks!!!

• Questions?

51
Change in Nitrogen Need by Year

• Data from NW Ohio corn after beans

Year Opt. N Yield
1998 187 239
1999 160 184
2000a 170 157
2000b 149 153
2001 233 189
2002 169 89
2003 218 237
2004 162 193
2005 175 204
Avg 187 181