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CANOPY REFLECTANCE (HRWW AND HRSW) IN SOUTH DAKOTA

ECONOMIC OPTIMUM NITROGEN RATE FOR HRSW IN SOUTH DAKOTA

Nitrogen Use Efficiency Meeting

Cheryl Reese*, David Clay*, Dwayne Beck*, John Lukuch‡, Tulsi Kharel*, Sharon Clay*, Dan Long†, and

Gregg Carlson**South Dakota State University, Brookings, SD‡ North Dakota State University, Langdon, ND

†USDA-ARS, Pendleton, Oregon

August 3rd, 2010Stillwater, Oklahoma

Objectives

• Improve N fertilizer recommendations for South Dakota Wheat

• Evaluate canopy reflectance to predict N

• EONR and impact of protein premium / discount

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Study Location

Study Location

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Hard Red Winter WheatCanopy

Reflectance

Field Locations

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HRWW Study Locations

Winner, SD

Remote Sensing Equipment: CropScan, Passive 16 Band Radiometer

• Passive Sensor• Depend on sunlight• Trade-off: collect over wide range, ability to

select wavelengths, and wavebands

Indices

Description IndexCropscan Bands Used to Calculate

IndexMeasurement Authors

Normalized Difference Vegetation

Index

NDVIw

(R830 - R660)(R830 + R660)

Healthy vegetation

reflects more NIR and less visible light.

Rouse, 1973

NDVIn

(R760 - R660) (R760 + R660)

Green Normalized Difference Vegetation

Index

GNDVIw

(R830 - R560) (R830 + R560) More sensitive

to chlorophyll-a than NDVI.

Gitelsonet al., 1996

GNDVIn

(R870 - R568)(R870 + R568)

CRedEdge CRedEdge [R810 / R710]-1Canopy

chlorophyll

Gitelsonet al., 2005

Dakota Lakes, HRWW 2006:Good year for line source irrigation

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• 04/26/06:– 3-4 leaf,

tillering• 05/11/06:

– Jointing• 05/26

– Boot, – Some awns

visible

04/26/06

05/11/06

Dakota Lakes, Canopy Reflectance

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HRWW Yield and Protein

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ParameterN rate

kg-N ha-1 Water kg ha-1 bu A-1

0 6796 10190 6453 96

180 5602 83270 4289 640 3842 5790 3596 53

180 3871 57270 3500 520 1334 2090 1219 18

180 1306 19270 1550 230 1187 1890 982 15

180 938 14270 1255 19

P value <0.01 <0.01LSD (0.05) 746 11

High Water

Moderate High

Moderate Low

Natural (Low)

Yield Main effects Protein

kg-N ha-1g-protein kg-grain-1

0 12.990 15.0180 16.6270 17.4P value <0.001LSD (0.05) 1.0WaterHigh 11.7Moderate 14.1Moderate Low 18.3Natural 17.7P Value <0.001LSD (0.05) 1.0

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HRSW,Dakota Lakes,

2003-2004Canopy

Reflectance, Yield, and

Protein

Field Cultural Practices

• No-Till for 20+ years• Wide variety of rotations

– Beneficial soil / mycorrhyzial interactions

• Average spring soil test NO3– 60 kg-N ha-1

• Previous crop– 2003: Soybeans– 2004: Pinto beans and cowpeas

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Growth Stages• May 15th

– 3-4 leaf, tillering• June 4th

– 6 leaf, end of tillering• June 14th

– Flag leaf, some awns• June 26th

– Flowering

Saturation Issues

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NDVIw NDVIn

CRedEdgeGNDVIn

ResultsWhich would you select?

NDVI in SD, HRSW

• Monitor growth stage carefully,

• Collect NDVI before canopy closure to avoid saturation issues

• Around Memorial Day Weekend (End of May, Beginning of June)

Lodging Heads ProteinN Rate (kg ha-1) N Time

1=none 9=all

number / plant kg ha-1 bu a-1

g-protein kg-grain-1

0 0 2.0 3873 58 114100 Pre-E 4 2.8 3905 58 139200 Pre-E 6 2.6 3513 52 152133 Haun 5-6 3 2.9 4167 62 148200 Haun 5-6 3 2.7 3936 59 15167/133 Split 6 2.9 3770 56 152

<0.001 <0.01 <0.001 <0.001 <0.0011 0.7 184 3 7

Nitrogen

P ValueLSD (0.05)

Yield

Harvest Parameters

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Summary: HRSW

• NDVI values should be collected before 5-6 leaf on HRSW (~May 28th or Memorial Day in South Dakota).

• If N is to be applied after 5-6 leaf, CRedEdge appeared to be a

• This study suggests when soil NO3-N is ~60 kg-N ha-1, 130 kg-N ha-1applied 5-6 leaf increases yield, grain protein, and reduces lodging.

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How Much N Fertilizer to

Apply on HRSW?What Pays?

What Does Not Pay?

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What Farmers Know at Planting

• N Fertilizer Cost• In SD, with HRSW, some indication

of yield and quality in Kansas, Oklahoma, Texas

• When they have lost $ in the past due to discount on low protein wheat

• When they have made $ with a premium

• Fertilize for protein @ 12% HRWW, @ 14% HRSW

FIELD LOCATIONS

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Study Locations

HRSW grain market value in SD based on protein premium or discount.

758595

105115125135145155165175

9/1/1998

9/1/1999

9/1/2000

9/1/2001

9/1/2002

9/1/2003

9/1/2004

9/1/2005

9/1/2006

9/1/2007

9/1/2008

Date

$ M

g-1

Discount at 10% ProteinPremium at 16% Protein

Line at $129 Mg-1 is 140-g protein kg-grain-1

where protein premium or discount is zero

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South Dakota, July 30th, 2010 Commodity Prices & Premium/Discount

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Experimental Design• RCB Design, Each Site, 4 Blocks. • N Treatments:

Pre-Emergence N

In-Season N Haun 5-6

Site N Treatment Name

Zero N 0 0Pre-E Moderate 100 0

Pre-E High 200 0In-S Moderate 0 133

In-S High 0 200Split 67 133

Zero N 0 0Pre-E Moderate 100 0

Pre-E High 150 0In-S Moderate 0 100

In-S High 0 150Split 50 100

Dakota Lakes 2003 and

2004, mixed grass prairie

Langdon 2004 - 2007, tall

grass praririe

kg-N ha-1

Determined Apparent Return and EONR

Calculating Return on N InvestmentApparent Return ($ ha-1)

• Two grain selling price– $129 or $258 Mg-1 ($3.50 or 7.00 bushel-1)

• Three N fertilizer costs– $0.62, $1.25, or $1.90 kg-N-1 or – ($0.28, $0.57, or $0.86 lb-N-1)

• Six Protein Premium / Discount Scenarios• N applied Pre-Emergence or In-Season

)ha N-kg ($ Cost N kg ($ Price x )ha (kg Yield

)ha ($ Return Apparent1-1-1-

-1

)

1 $/kg N $ kg/ha)N$/kg wheat$ kg/ha) Yield

$/ha N costd$/ha wheatvalue

(d

(dd

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100 140 160Description

Zero, no discount or premium

129 129 129

Discount only 122 129 129

Low discount & average premium

122 129 147

Moderate discount & average premium

105 129 147

High discount & average premium

90 129 147

Low discount & high premium

122 129 161

Zero, no discount or premium

257 257 257

Discount only 244 257 257

Low discount & average premium

244 257 293

Moderate discount & average premium

209 257 293

High discount & average premium

179 257 293

Low discount & high premium

244 257 322

METRIC

Low Grain Value, $129 MG -1

High Grain Value, $257 MG -1

g-protein kg-grain-1

Grain Value 10 14 16

Description

Zero, no discount or premium

3.50 3.50 3.50

Discount only 3.32 3.50 3.50

Low discount & average premium

3.32 3.50 4.00

Moderate discount & average premium

2.86 3.50 4.00

High discount & average premium

2.45 3.50 4.00

Low discount & high premium

3.32 3.50 4.38

Zero, no discount or premium7.00 7.00 7.00

Discount only 6.64 7.00 7.00

Low discount & average premium

6.64 7.00 7.97

Moderate discount & average premium

5.69 7.00 7.97

High discount & average premium

4.87 7.00 7.97

Low discount & high premium

6.64 7.00 8.76

ENGLISH

Low Grain Value, $3.50 bushel -1

High Grain Value, $7.00 bushel -1

% Protein

Grain Value

$0.62$1.25$1.90$0.62$1.25$1.90$0.62$1.25$1.90

$0.62$1.25$1.90$0.62$1.25$1.90$0.62$1.25$1.90

High discount

High premium

High discount

High premium

Zero

Discount only

Low discount

Moderate discount

Use $ kg-grain-1

from yield N response function

and subtract N fertilizer cost to obtain Apparent Return ($ ha-1)

Use Excel Solver™ to Maximize

Apparent Return ($ ha-1) Based on kg-N ha-1 Applied

and Determine EONR

Determine $ kg-grain-1 based on yield N response

function and protein premium / discount scenario

Zero

Discount only

Low discount

Moderate discount

257

129

Protein N Response Function

Run each scenario through Excel

Solver™ to determine EONR $129 or

$257 Mg-1

$0.62, $1.25 or

$1.90 kg-N-1

Determine grain protein based on

protein N response function

Select Grain Selling Value

Select N Fertilizer

Cost

Determine Apparent Return ($ ha-1) Using Eqn. 3.6

EONR Using Excel SolverTM

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Results: Apparent

Return, and Economic

Optimum N Rate(EONR),Yield, and Protein

Nitrogen Treatment Impact for Different Protein Premium / Discount Scenarios on

Apparent Return ($ ha-1)

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0.62 1.25 1.90 0.62 1.25 1.90

Zero

Discount Only

Low Discount

Mod. or High N Applied In-S

Moderate Discount

High Discount

High Premium

Mod. or High N Applied In-S

Zero or Mod. N Applied In-S

Moderate N Applied Pre-E

or In-SZero N

Moderate N Applied Pre-E

Zero

Moderate N Applied Pre-E or In-SHigh N

Applied In-S

Protein Premium or

Discount Scenario

Grain Value ($129 Mg-1)

N Fertilizer Cost ($ kg-N-1)

Grain Value ($258 Mg-1)

N Treatment w/ Greatest Apparent Return, $ ha-1

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EONR: Application TimePre-Emergence or In-Season?

• Tested 36 scenarios:– Six Sites– Three fertilizer prices– Two grain selling prices

• Out of these:– EONR In-S or Pre-emergence the

same: 22 scenarios– In-S EONR Higher: 10– Pre-emergence EONR Higher: 4

Fertilizer Cost and EONR: % N Fertilizer Reduction

$ kg-N-1EONR kg-N ha-1

(@$258 Mg-1)EONR kg-N ha-1

(@$129 Mg-1)%

Reduction0.62 110 89 191.25 89 47 471.90 63 24 62

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EONR at Langdon and Rainfall• $129 Mg-1 a)

$0.62 kg-N-1

EONR = 1.4 (cm rain) + 31.1R2 = 0.38

$1.25 kg-N-1

EONR = 2.3 (cm rain) - 66.1R2 = 0.66

$1.90 kg-N-1

EONR = 1.3 (cm rain) - 36.2R2 = 0.27

020406080

100120140160

40 50 60 70cm rainfall

EON

R (k

g-N

ha-1

)

$0.62 $1.25 $1.90

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Need Rain forin-season N

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Conclusions• Indices show great promise in SD to

manage in-season N for both HRWW and HRSW; need more fields.

• N fertilizer price affects wheat EONR. • Development of a online EONR

prediction model for wheat incorporating:– N fertilizer cost options– Value of grain– Different protein premium/discounts

scenarios– Tillage / Climate Impacts on N mineralization:

• Microorganism competition for N• Mycorrhizal colonization and contributions

EONR Calculator for Wheat

Central tall grass prairie Discount PremiumNorthern mixed grass prairie Zero ZeroNorthern short grass prairie Discount Only Zero

Low Discount Moderate PremiumModerate Discount Moderate PremiumHigh Discount Moderate PremiumLow Discount High Premium

ORSet protein

14%

Non-Responsive sitesYesNo

Select N source$250 $325 $400 $475 $ / ton-fertilizer$0.45 $0.58 $0.71 $0.85 $ / lb-N$5.00 $5.00 $5.00 $5.00 $ / bu

Nitrogen PriceWheat Price

Choose Protein Discount / PremiumChoose Region

UAN (28%)

Set N fertilizer cost and wheat selling price

Questions / Thank you!

Scientists:• David Clay (SDSU)• Sharon Clay (SDSU)• Dwayne Beck (SDSU)• Gregg Carlson (SDSU)• Dan Long (USDA-ARS)

Farmers and Support Staff at SDSU

• Dan Forgey (Farmer)• Ralph Holzwarth (Farmer)• Ryan Patterson (Farmer)• Steph Hansen (SDSU)• Jon Kleinjan (SDSU)• Ryan Brunner (SDSU)• Tulsi Kharel (SDSU) 36

South Dakota State University

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Yield, Lodging, and Grain

Protein

LodgingGrain

Protein

kg ha-1 bu a-11= none 9

= allg-protein kg-grain-1

SiteDakota Lakes 2003 3735 56 4.2 152

Dakota Lakes 2004 3986 59 3.2 135

Langdon 2004 3938 59 1 135

Langdon 2005 4513 67 2.5 144

Langdon 2006 3190 47 1 142

Langdon 2007 3462 51 1.8 137

P Value <0.001 <0.001 <0.001 <0.001LSD (0.05) 187 3 0.7 4

N Time/RateZero N 3392 50 1.1 121

Pre-E, Moderate 3894 58 2.5 140

Pre-E, High 3799 57 3.6 146

Haun 5-6, Moderate 3844 57 2 144

Haun 5-6, High 3939 59 1.6 148

Split, Pre-E & Haun 5-6 3956 59 3 146

P Value <0.001 <0.001 <0.001 <0.001LSD (0.05) 198 3 0.8 5

Grain Yield

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05/26/2006

Winner Field, 2006:A Challenging Field

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