1. Determining Nitrogen Application Rates with SBNRC and RAMP Calculator

2. IKONIS Satellite Image of a Wheat Field Covington, Oklahoma
Bottom Formerly in Alfalfa
Eroded Hillside
N-Rich 140 lb/ac
Farm Rate 70 lb/ac
44 bu/ac farm
Alfalfa Field Yield bu/ac
IKONIS Satellite Image of a Wheat Field Covington, Oklahoma
NRich Strip NDVI Map

3. Algorithm to Calculate N Rate with SBNRC3
2001
YPN <= YPMAX 1
Predict RI
Predict YP0
Predict YPN based on RI
Fertilizer N = (GNUP-FNUP)/0.5 2 2 3 4 1 4

4. Ramp Concept
Courtesy Larry Riechenberger

5. Idealized 16 Step Calibration Ramp
NRich NDVI
Field Rate NDVI
Ramp Max or Upper Limit N Application Rate
YP0
YPMax

6. Determining N Rate Using the RAMP Calculator
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
13.3
26.7
34.0
53.3
66.7
80.0
93.3
106.7
120.0
133.3
146.7
160.0
173.3
187.7
200.0
Ramp N Rates, lb/ac
NDVI
Determine Transition Curve
Determine Plateau
Optimum Fall Applied N Rate
Calculating Topdress N Rate

7. Which Part of the Ramp Do We Measure?
Do Not Sense
Sense

8. MorrisonDemo Recommended Nitrogen Rate Average Rep 1 Rep 2 SBNRC 28 3324
Ramp Analysis 32 16 17

9. T04 Recommended Nitrogen Rate Average Rep 1 Rep 2 SBNRC 44 2 87
Ramp Analysis 55 3
107*
*Flag Too High Rate

10. T24 Recommended Nitrogen Rate Average Rep 1 Rep 2 SBNRC 63 62 64
Ramp Analysis 34 38 31

11. Recommendations
Use the SBNRC with either the RAMP or NRich Strip to determine inputs to NTECH GreenSeeker sprayer
The SBNRC and NRich strip works well provided you measure in the area of maximum response
The SBNRC provides and estimate of yield with and without additional N fertilizer
The SBNRC will calculate gross returns with and without additional N

12. Recommendations
The SBNRC and the RAMP calculator will give the most precise estimate of potential of field NDVI and N non-limiting NDVI
Use the SBNRC and the RAMP calculator if you want two independent estimates of the topdress N rate.