Corn Nitrogen Management: Corn Nitrogen Management: Progress in MissouriProgress in Missouri

Corn Nitrogen Management: Corn Nitrogen Management: Progress in MissouriProgress in Missouri

Newell R. Kitchen, Kenneth A. Sudduth, and Newell R. Kitchen, Kenneth A. Sudduth, and John HummelJohn Hummel USDA-ARS, Columbia, MOUSDA-ARS, Columbia, MO

Peter Scharf, Harlan Palm, and Kent ShannonPeter Scharf, Harlan Palm, and Kent Shannon Univ. of MO, Columbia, MOUniv. of MO, Columbia, MO

Newell R. Kitchen, Kenneth A. Sudduth, and Newell R. Kitchen, Kenneth A. Sudduth, and John HummelJohn Hummel USDA-ARS, Columbia, MOUSDA-ARS, Columbia, MO

Peter Scharf, Harlan Palm, and Kent ShannonPeter Scharf, Harlan Palm, and Kent Shannon Univ. of MO, Columbia, MOUniv. of MO, Columbia, MO

Over the YearsOver the YearsOver the YearsOver the Years

Yield Mapping (1992-1996)Yield Mapping (1992-1996)

Soil EC (1993-1998)Soil EC (1993-1998)

Ambient Light Radiometers (1997-2002)Ambient Light Radiometers (1997-2002)

Aerial Photos (1999-2001)Aerial Photos (1999-2001)

Soil Sampling for Inorganic N (1999-2002)Soil Sampling for Inorganic N (1999-2002)

Characterizing Within-Field EONR (1999-2002)Characterizing Within-Field EONR (1999-2002)

Sensing Technologies for Precision Farming, Sensing Technologies for Precision Farming, IFAFS grantIFAFS grant (2002-2005) (2002-2005)

Yield Mapping (1992-1996)Yield Mapping (1992-1996)

Soil EC (1993-1998)Soil EC (1993-1998)

Ambient Light Radiometers (1997-2002)Ambient Light Radiometers (1997-2002)

Aerial Photos (1999-2001)Aerial Photos (1999-2001)

Soil Sampling for Inorganic N (1999-2002)Soil Sampling for Inorganic N (1999-2002)

Characterizing Within-Field EONR (1999-2002)Characterizing Within-Field EONR (1999-2002)

Sensing Technologies for Precision Farming, Sensing Technologies for Precision Farming, IFAFS grantIFAFS grant (2002-2005) (2002-2005)

Adoption is being hindered because of lack of convenience.

Peter Nowak, 7th Int. Conf. on Precision Agriculture, July 26, 2004

Adoption is being hindered because of lack of convenience.

Peter Nowak, 7th Int. Conf. on Precision Agriculture, July 26, 2004

Nitrogen Cycle

OutlineOutlineOutlineOutline

Sub-Field Economic Optimal N RateSub-Field Economic Optimal N Rate

Plant-Specific N Application in CornPlant-Specific N Application in Corn

Field Testing of VR N Applicator Using Field Testing of VR N Applicator Using Active Light SensorsActive Light Sensors

Sub-Field Economic Optimal N RateSub-Field Economic Optimal N Rate

Plant-Specific N Application in CornPlant-Specific N Application in Corn

Field Testing of VR N Applicator Using Field Testing of VR N Applicator Using Active Light SensorsActive Light Sensors

Sub-field Economic Optimal N RateSub-field Economic Optimal N RateSub-field Economic Optimal N RateSub-field Economic Optimal N Rate3 soil types: Mississippi delta, loess, claypan3 soil types: Mississippi delta, loess, claypan

3 years: 2000-20023 years: 2000-2002

Producers’ fieldsProducers’ fields

Treatments were field-length strips of discrete N Treatments were field-length strips of discrete N rates from 0 to 280 kg N ha-1 in 56-kg rates from 0 to 280 kg N ha-1 in 56-kg increments. increments.

Plots were six rows wide (4.5 m) and ranged in Plots were six rows wide (4.5 m) and ranged in length from 400 to 1000 m. length from 400 to 1000 m.

Corn grain was harvested from the center four Corn grain was harvested from the center four rows of each plot using a combine equipped with rows of each plot using a combine equipped with a yield monitor and corn population sensors a yield monitor and corn population sensors

3 soil types: Mississippi delta, loess, claypan3 soil types: Mississippi delta, loess, claypan

3 years: 2000-20023 years: 2000-2002

Producers’ fieldsProducers’ fields

Treatments were field-length strips of discrete N Treatments were field-length strips of discrete N rates from 0 to 280 kg N ha-1 in 56-kg rates from 0 to 280 kg N ha-1 in 56-kg increments. increments.

Plots were six rows wide (4.5 m) and ranged in Plots were six rows wide (4.5 m) and ranged in length from 400 to 1000 m. length from 400 to 1000 m.

Corn grain was harvested from the center four Corn grain was harvested from the center four rows of each plot using a combine equipped with rows of each plot using a combine equipped with a yield monitor and corn population sensors a yield monitor and corn population sensors

Oran00 Rep1 Block6

0

4

8

12

16

0 100 200 300

N rate (kg ha-1)

Yie

ld (

Mg

ha-1

)

Nopt

Oran00 Rep3 Block26

0

4

8

12

16

0 100 200 300

N rate (kg ha-1)

Yie

ld (

Mg

ha-1

)

Nopt

Deriving Spatially Variable Deriving Spatially Variable Economic Optimum N RateEconomic Optimum N RateDeriving Spatially Variable Deriving Spatially Variable Economic Optimum N RateEconomic Optimum N Rate

N rates, kg/ha

0 to 80

80 to 120

120 to 160

160 to 200

200 to 280

Economic Optimum N RateEconomic Optimum N RateClaypan Soil Field 2001Claypan Soil Field 2001

Ec

on

om

ica

lly

Op

tim

al

N R

ate

, k

g h

a -1

RA

TE

300

250

200

150

100

350

300

DL00 DL01MD00 MD01CP00 CP01 DL02 MD02

** *

*

**

*

*

whisker: rangebox: 25th to 75th percentilebox line: medianplus sign : meanasterisk: N rate based on mass balance and actual field-average yield

D L 0 2

R 2 = 0 . 0 3

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

0 . 0 3 . 0 6 . 0 9 . 0 1 2 . 0 1 5 . 0Ec

on

om

ica

lly

O

pt

ima

l N

itr

og

en

R

at

e,

k

g

ha

-1

Y i e l d a t E c o n o m i c a l l y O p t i m a l N i t r o g e n R a t e , M g h a - 1

C P 0 0

R 2 = 0 . 1 2

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

0 . 0 3 . 0 6 . 0 9 . 0 1 2 . 0 1 5 . 0

C P 0 1

R 2 = 0 . 5 4

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

0 . 0 3 . 0 6 . 0 9 . 0 1 2 . 0 1 5 . 0

D L 0 0

R2

= 0 . 0 3

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

0 . 0 3 . 0 6 . 0 9 . 0 1 2 . 0 1 5 . 0

D L 0 1

R2

= 0 . 2 2

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

0 . 0 3 . 0 6 . 0 9 . 0 1 2 . 0 1 5 . 0

M D 0 0

R2

= 0 . 0 1

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

0 . 0 3 . 0 6 . 0 9 . 0 1 2 . 0 1 5 . 0

M D 0 1

R2

= 0 . 0 9

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

0 . 0 3 . 0 6 . 0 9 . 0 1 2 . 0 1 5 . 0

D L 0 2

R 2 = 0 . 0 3

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

0 . 0 3 . 0 6 . 0 9 . 0 1 2 . 0 1 5 . 0

M D 0 2

R2

= 0 . 2 0

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

0 . 0 3 . 0 6 . 0 9 . 0 1 2 . 0 1 5 . 0

Ec

on

om

ica

lly O

pti

ma

l N

itro

ge

n R

ate

, k

g h

a-1

Y i e l d a t E c o n o m i c a l l y O p t i m a l N i t r o g e n R a t e , M g h a - 1

The Take HomeThe Take HomeThe Take HomeThe Take Home

EONR is highly variable within Missouri EONR is highly variable within Missouri corn fields, and between fieldscorn fields, and between fields

EONR is highly-dependent on yearly EONR is highly-dependent on yearly climate conditionsclimate conditions

Yield is not a very poor predictor of EONRYield is not a very poor predictor of EONR

EONR is highly variable within Missouri EONR is highly variable within Missouri corn fields, and between fieldscorn fields, and between fields

EONR is highly-dependent on yearly EONR is highly-dependent on yearly climate conditionsclimate conditions

Yield is not a very poor predictor of EONRYield is not a very poor predictor of EONR

Plant-Specific N Application in CornPlant-Specific N Application in CornPlant-Specific N Application in CornPlant-Specific N Application in Corn

Field studies have shown increased corn yield with better Field studies have shown increased corn yield with better plant uniformity, which generally was measured by plant-plant uniformity, which generally was measured by plant-spacing standard deviation (Krall et al., 1977; Nielson, spacing standard deviation (Krall et al., 1977; Nielson, 1991; Doerge et al., 2002).1991; Doerge et al., 2002).

The variability of plant spacing is primarily caused by one The variability of plant spacing is primarily caused by one of the following: of the following: – skips due to either un-dropped seeds or non-emerged seedlings, skips due to either un-dropped seeds or non-emerged seedlings, – double, triple or more plants, where two or more seeds take the double, triple or more plants, where two or more seeds take the

place of one,place of one,– misplaced plants, shifted from its designated location towards misplaced plants, shifted from its designated location towards

one of the within-row neighbors one of the within-row neighbors

Field studies have shown increased corn yield with better Field studies have shown increased corn yield with better plant uniformity, which generally was measured by plant-plant uniformity, which generally was measured by plant-spacing standard deviation (Krall et al., 1977; Nielson, spacing standard deviation (Krall et al., 1977; Nielson, 1991; Doerge et al., 2002).1991; Doerge et al., 2002).

The variability of plant spacing is primarily caused by one The variability of plant spacing is primarily caused by one of the following: of the following: – skips due to either un-dropped seeds or non-emerged seedlings, skips due to either un-dropped seeds or non-emerged seedlings, – double, triple or more plants, where two or more seeds take the double, triple or more plants, where two or more seeds take the

place of one,place of one,– misplaced plants, shifted from its designated location towards misplaced plants, shifted from its designated location towards

one of the within-row neighbors one of the within-row neighbors

0 0.2 0.4 0.6 0.8 1 1.2Plant spacing, m

0

0.004

0.008

0.012R

ela

tive

fre

quen

cy

High-Speed Population DataHigh-Speed Population Data(1-mm resolution)(1-mm resolution)

ObjectiveObjectiveObjectiveObjective

To evaluate the agronomic response of To evaluate the agronomic response of corn plants to varying N fertilizer rate on a corn plants to varying N fertilizer rate on a plant-by-plant basis in conjunction with plant-by-plant basis in conjunction with plant spacing scenarios. plant spacing scenarios.

To evaluate the agronomic response of To evaluate the agronomic response of corn plants to varying N fertilizer rate on a corn plants to varying N fertilizer rate on a plant-by-plant basis in conjunction with plant-by-plant basis in conjunction with plant spacing scenarios. plant spacing scenarios.

1) Uniform X X X X X X X X

2) Single Skip X X X X X X X X

3) Double Skip X X X X X X X X

4) Double PlantX X X XX X X X

Plant Spacing Scenarios

Nitrogen Treatments1) No N

2) Adequate N, 269 kg N ha-1 shortly after emergence

Treatments at or about V8 growth stage

3) Equal N, 179 kg N ha-1

4) VR1 “Robin Hood”, …179-224-134-134-224-179…. kg N ha-1 for UN, SS, and DS and …179-134-224-134-179…kg N ha-1 for DP (treated as one plant)

5) VR2 “Sheriff of Nottingham”, …179-134-224-224-134-179…kg N ha-1 for UN, SS, and DS and …179-224-134-224-179… kg N ha-1 for DP

Two Sites in 2003/ Three Sites in 2004

0.00

2.00

4.00

6.00

8.00

10.00

12.00

1

Plant Scenario

Yie

ld (

Mg

/ha)

Uniform Single Skip

Double Skip

Double

a

bc

d

Irrigated Site 2003

0.00

2.00

4.00

6.00

8.00

10.00

12.00

1

Nitrogen Treatments

Yie

ld (

Mg

/ha)

Adequate Equal VR 1 VR 2 No N

ab

abb

c

Irrigated Site 2003

The Take HomeThe Take HomeThe Take HomeThe Take Home

Field Testing of VR N Applicator Field Testing of VR N Applicator Using Active Light SensorsUsing Active Light Sensors

ProceduresProceduresProceduresProcedures

Seven producer fields as research sitesSeven producer fields as research sitesUAN + Agrotain for all N treatmentsUAN + Agrotain for all N treatmentsReference N strips were applied shortly after emergenceReference N strips were applied shortly after emergenceVR and CR treatments were done at knee/waist-high VR and CR treatments were done at knee/waist-high corn, and also shoulder-high corn at two sitescorn, and also shoulder-high corn at two sites6-row treatment strips, sensors over row 2 and 5 and 6-row treatment strips, sensors over row 2 and 5 and averaged for calculationsaveraged for calculationsAlgorithm used was developed based on radiometer Algorithm used was developed based on radiometer measurements taken from small plot studies from 1998-measurements taken from small plot studies from 1998-99 (unpublished)99 (unpublished)Sites include 16-m long response plots to be hand Sites include 16-m long response plots to be hand harvestedharvested

Seven producer fields as research sitesSeven producer fields as research sitesUAN + Agrotain for all N treatmentsUAN + Agrotain for all N treatmentsReference N strips were applied shortly after emergenceReference N strips were applied shortly after emergenceVR and CR treatments were done at knee/waist-high VR and CR treatments were done at knee/waist-high corn, and also shoulder-high corn at two sitescorn, and also shoulder-high corn at two sites6-row treatment strips, sensors over row 2 and 5 and 6-row treatment strips, sensors over row 2 and 5 and averaged for calculationsaveraged for calculationsAlgorithm used was developed based on radiometer Algorithm used was developed based on radiometer measurements taken from small plot studies from 1998-measurements taken from small plot studies from 1998-99 (unpublished)99 (unpublished)Sites include 16-m long response plots to be hand Sites include 16-m long response plots to be hand harvestedharvested

N Rec = -200 +250

VisibleNIR

VisibleNIR

Target

Reference

(( )

)N Rec = -200 +250

VisibleNIR

VisibleNIR

Target

Reference

(( )

)

- Ceiling for Reference set to 0.25

Algorithm for Knee- to Waist-High CornAlgorithm for Knee- to Waist-High CornAlgorithm for Knee- to Waist-High CornAlgorithm for Knee- to Waist-High Corn

Algorithm for Shoulder-High CornAlgorithm for Shoulder-High CornAlgorithm for Shoulder-High CornAlgorithm for Shoulder-High Corn

- Ceiling for Reference set to 0.25

N Rec = -150 +180

VisibleNIR

VisibleNIR

Target

Reference

(( )

)N Rec = -150 +180

VisibleNIR

VisibleNIR

Target

Reference

(( )

)

0

50

100

150

200

250

1.0 1.2 1.3 1.5 1.6 1.8 1.9 2.1

Ratio of Sensor Readings

Nit

rog

en R

ate

(lb

/A)

knee/waist

shoulder

553600 553700

4289400

4289450

4289500

4289550

4289600

4289650

4289700

4289750

4289800

4289850

4289900

4289950

0 .11 to 0.1808 0.1808 to 0.2032 0.2032 to 0.2236 0.2236 to 0.2439 0.2439 to 0.2678 0.2678 to 0.2962 0.2962 to 0.3344 0.3344 to 0.3899 0.3899 to 0.4837 0.4837 to 0.9032

Reference Strips

Ratio

454200 454250454200 454250

4310300

4310350

4310400

4310450

4310500

0.10.120.140.160.180.20.220.240.260.280.30.320.340.360.380.40.420.440.460.480.50.520.540.560.58

454200 454250

4310300

4310350

4310400

4310450

4310500

6 0

7 0

8 0

9 0

1 0 0

1 1 0

1 2 0

1 3 0

1 4 0

1 5 0

1 6 0

1 7 0

1 8 0

1 9 0

2 0 0

2 1 0

A p p l i c a t i o n R a t e M e a n = 9 7 l b / A

R e f e r e n c e Y / N I R R a t i o A c t u a l Y / N I R R a t i o

0

50

100

150

200

250

1.0 1.2 1.3 1.5 1.6 1.8 1.9 2.1

Ratio of Sensor Readings

Nit

rog

en R

ate

(lb

/A)

knee/waist

shoulder

Research supported in part by the USDA- NRI and IFAFS Grant Programs. Assistance also given by OSU, NTech, and Holland Instruments.