New Technology and New Technology and Strategies for Nitrogen Strategies for Nitrogen

Management Management

Traditional N Traditional N RecommendationsRecommendations

2 lbs/bushel of wheat2 lbs/bushel of wheat 1.2 lbs/bushel of corn1.2 lbs/bushel of corn 50 lbs/ton of bermudagrass50 lbs/ton of bermudagrass 60 lbs/ton of fescue, small grain 60 lbs/ton of fescue, small grain

pasturepasture

Lahoma 502, 30-yr Averages

0

10

20

30

40

50

0 20 40 60 80 100 120N Rate (lb/acre)

Whe

at Y

ield

(b

u/ac

re)

Lahoma 502, 30-yr Averages

0

10

20

30

40

50

0 20 40 60 80 100 120N Rate (lb/acre)

Whe

at Y

ield

(b

u/ac

re)

Average profit from N = $36/acre/yrAverage profit from N = $36/acre/yrAverage profit from N = $36/acre/yrAverage profit from N = $36/acre/yr

Conventional Strategy is Conventional Strategy is Easy and Profitable.Easy and Profitable.

Conventional Strategy is Conventional Strategy is Easy and Profitable.Easy and Profitable.

Crop N requirement = 2 lb N/bu yieldCrop N requirement = 2 lb N/bu yieldCrop N requirement = 2 lb N/bu yieldCrop N requirement = 2 lb N/bu yield

Temporal and Spatial Temporal and Spatial VariabilityVariability

In season environmental conditions

Within field variability

What Scale is Necessary for Precision Ag?

TemporalTemporal Variability VariabilityTemporalTemporal Variability Variability Historically, it was thought that if N was Historically, it was thought that if N was

not applied annually crop production not applied annually crop production would eventually deplete the soil of its N would eventually deplete the soil of its N reserve.reserve.

$17/A Benefit from in-season yield estimate

0

20

40

60

80

100

120

140

1971

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

Op

tim

um

N R

ate,

lb

/ac

Exp. 502, 1971-2005

Optimum N Rate Max YieldAvg. 49 lb N/ac +/- 39 Avg. 43 bu/ac +/- 13

Optimum N Rate (Grain N Uptake Max Yield – Grain N Uptake Check)/0.50Optimum N Rate (Grain N Uptake Max Yield – Grain N Uptake Check)/0.50

“After the FACT” N Rate required for “MAX Yields” Ranged from 0 to 140 lbs N/ac

Long-Term Winter Wheat ExperimentLahoma, OKLong-Term Winter Wheat ExperimentLahoma, OK

GreenSeekerGreenSeeker®® Sensor Sensor FunctionFunction

Emits Red & InfraRed Emits Red & InfraRed WavelengthsWavelengths

Outputs NDVIOutputs NDVI—— indicates Biomass and indicates Biomass and Plant VigorPlant Vigor

Day or Night UseDay or Night Use

No Effect from CloudsNo Effect from Clouds

Emits Red & InfraRed Emits Red & InfraRed WavelengthsWavelengths

Outputs NDVIOutputs NDVI—— indicates Biomass and indicates Biomass and Plant VigorPlant Vigor

Day or Night UseDay or Night Use

No Effect from CloudsNo Effect from Clouds

Normalized Difference Normalized Difference Vegetative Index - Vegetative Index - NDVINDVI Calculated from the Calculated from the

red and near-infrared red and near-infrared bandsbands

Measures BiomassMeasures Biomass Correlated with:Correlated with:

Plant biomassPlant biomass Crop yieldCrop yield Plant nitrogenPlant nitrogen Plant chlorophyllPlant chlorophyll Water stressWater stress Plant diseasesPlant diseases Insect damageInsect damage

Can Yield Potential (similar to “yield Can Yield Potential (similar to “yield goals”) be Predicted MID-SEASON?goals”) be Predicted MID-SEASON?

Sensor Reading

Winter Wheat, Enid, Winter Wheat, Enid, 20052005

0

10

20

30

40

50

60

70

80

197 171 144 118 92 66 39 13 0 26 52 79 105 131 158 184

N Rate, lb/ac

Yie

ld (

bu

/ac)

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

Sen

sor R

eadin

gs (N

DV

I) F

eekes 5

Yield NDVI

0 N

Handheld Unit – •Temporal Variability•In season environmental

conditions

Sensor Based Nitrogen Sensor Based Nitrogen RecommendationsRecommendations

N Rates Vary from one year to N Rates Vary from one year to the next, and field to fieldthe next, and field to field

When you fill up your gas tank, When you fill up your gas tank, do you put in 20 gallons every do you put in 20 gallons every time no matter what? time no matter what?

Sensors allow in season Sensors allow in season decisions for nitrogen rates decisions for nitrogen rates

Progress timelineProgress timeline 1991: Developed optical sensors and sprayer control systems to detect bindweed in fallow fields and to spot spray the

weed 1993: Sensor used to measure total N uptake in wheat and to variably apply N fertilizer. 1994: Predicted forage biomass and total forage N uptake using NDVI (Feekes 5). 1994: First application of N fertilizer based on sensor readings. N rate was reduced with no decrease in grain yield. 1996: Worlds first optical sensing variable N rate applicator developed at OSU 1997: OSU optical sensor simultaneously measures incident and reflected light at two wavelengths, (670 ±6 nm and 780

±6 nm) and incident light is cosine corrected enabling the use of calibrated reflectance. 1997: Variable rate technology used to sense and treat every 4 square 1998: Yields increased by treating spatial variability and OSU’s In-Season-Estimated-Yield (INSEY) 1998: INSEY refined to account for temporal variability 1999: Found that adjacent 4 square foot areas will not always have the same yield potential 1999: Entered into discussions with John Mayfield concerning the potential commercialization of a sensor-based N 2000: N fertilizer rate needed to maximize yields varied widely over years and was unpredictable; developed RI 2001: NDVI readings used for plant selection of triticales in Mexico. 2001: NFOA algorithm field tested in 2001, demonstrating that grain yields could be increased at lower N rates when N

fertilizers were applied to each 4 square feet (using INSEY and RI) 2002: Ideal growth stage in corn identified for in-season N applications in corn via daily NDVI sampling in Mexico as V8. 2003: CV from NDVI readings collected in corn and wheat were first used within NFOA’s developed at OSU. 2003: When site CV’s were greater than 18, recovery of maximum yield from mid-season fertilizer N applications was

not possible in wheat 2004: Calibration stamp technology jointly developed and extended within the farming community 2004: OSU-NFOA’s (wheat and corn) used in Argentina, and extended in China and India. 2005: USAID Grant allowed GreenSeeker Sensors to be delivered in China, India, Turkey, Mexico, Argentina, Pakistan,

Uzbekistan, and Australia. 2006: Delivery of 586 RAMPS and 1500 N Rich Strips (using RCS and SBNRC approaches respectively) in farmer fields

across Oklahoma resulted in an estimated service area exceeding 200,000 acres and increased farmer revenue exceeding $2,000,000.

Handheld Unit – •Temporal Variability•In season environmental conditions

Handheld GreenSeeker™ units located in several NE District Extension Offices

2005-2006 Wheat2005-2006 WheatGreenSeeker/N Rich StripGreenSeeker/N Rich Strip

1 Farm – 43 wheat fields – 1665 1 Farm – 43 wheat fields – 1665 AcresAcres

Traditional Program – 100 Traditional Program – 100 pounds N/Apounds N/A

Handheld GreenSeeker ($3600) Handheld GreenSeeker ($3600) Saved 149,529 lbs of Urea, Saved 149,529 lbs of Urea, $14.59/A, $24,300 $14.59/A, $24,300

Regional GreenSeeker Regional GreenSeeker Grain Yields - 2005Grain Yields - 2005

0

20

40

60

80

100

120

140

160

180

200

Gra

in Y

ield

(bu

/ac)

Check Farmer practice N-Rich GreenSeeker

Regional GreenSeeker Regional GreenSeeker ProfitsProfits

0

50

100

150

200

250

300

350

Pro

fit

($/a

c)

Check Farmer practice N-Rich GreenSeeker

2006 NE GreenSeeker/Corn 2006 NE GreenSeeker/Corn TrialsTrials

Gross Return ($/A)Gross Return ($/A)

Treatment

Miami

South Coffeyville

Webbers Falls

Ft. Gibson

All Site Average

Check

228

253

270

375

282

Farmer Practice

203

259

265

289

254

N-Rich

141

171

351

324

247

75 lbs N – Pre+

GreenSeeker

175

272

346

367

290

0 N – Pre+

GreenSeeker

209

280

333

348

293

2006 NE GreenSeeker/Corn 2006 NE GreenSeeker/Corn TrialsTrials

Grain Yield (Bu/A)Grain Yield (Bu/A)

Treatment

Miami

South Coffeyville

Webbers Falls

Ft. Gibson

All Site Average

Check

91

101

108

150

113

Farmer Practice

92

122

144

153

128

N-Rich

102

114

186

175

144

75 lbs N – Pre+

GreenSeeker

87

123

155

167

133

0 N – Pre+

GreenSeeker

89

120

140

150

125

2006 NE GreenSeeker/Corn 2006 NE GreenSeeker/Corn TrialsTrials

Total N Applied (lbs N/A)Total N Applied (lbs N/A)

Treatment

Miami

South Coffeyville

Webbers Falls

Ft. Gibson

All Site Average

Check

0

0

0

0

0

Farmer Practice

70

120

250

246

172

N-Rich

300

300

300

300

300

75 lbs N – Pre+

GreenSeeker

112 (37)

93 (17)

110 (35)

132 (57)

112 (37)

0 N – Pre+

GreenSeeker

36

52

45

71

51

Calibration StampCalibration Stamp

Visual Interpretation of “Stamps” provides mid-season fertilizer N recommendation

Nitrogen Stamp

N Stamps applied – Nov. 16, 2004

80 N120 N40 N

N Stamp – Sperry, OK Jan 27, 2005Wheat planted Sept. 30, 2004

Optical Sensor Alternative N Stamps

40 lbs N 80 lbs N 120 lbs N

Ottawa CountyFebruary 15, 2005

GDD 74NDVI N Rich .562NDVI FP .364 Yield Potential 0 N – 42 bushelsYield Potential + N – 73 bushelsN recommedation – 75 lbs./A

Distance

N RateN Rate0 50 100 1500 50 100 150

ND

VI

ND

VI

RI = 1.5RI = 1.5

RI = 1.5RI = 1.5

N Ramp Calibration Strip

N Ramp Calibration Strip

0

20

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160

0 20 40 60 80 100

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280

300

Distance, ft

N R

ate

, lb

/ac

Ramp Calibration StripRamp Calibration Strip Walk it offWalk it off Or use Hand-Held SensorOr use Hand-Held Sensor

Walk it offWalk it off Or use Hand-Held SensorOr use Hand-Held Sensor

0 N0 N

195 N195 N

RAMP Calibration StripsRAMP Calibration Strips Ramped calibration strip is Ramped calibration strip is

superior than yield based N superior than yield based N recommendationrecommendation

It can be easily implemented, be It can be easily implemented, be used for other fertilizers and used for other fertilizers and amendmentsamendments

0 N

325 N

200 N

McIntosh County 2007Visual Estimate from Ramp

0 N

200 N

Delaware County 2007Visual Estimate from Ramp

325 N

We have the capability to fertilize individual plants

Soil Testing Still NeededSoil Testing Still Needed

Every 3 years or lessEvery 3 years or less Routine test for P,K, pHRoutine test for P,K, pH To diagnose production To diagnose production

problemsproblems