Optimizing Nitrogen Fertilizer Through Use of Optical

Sensors

Brian ArnallOklahoma State University

b.arnall@okstate.edu

Why Change

• Notill = More Organic Matter• Organic Matter is a Major Driver of N Cycle• New crops, new rooting structure• Higher Yields?

Sensor Based Nitrogen Rate Calculator?What is needed for a

Yield Prediction ModelResponse IndexNitrogen Removal

The calculation looks like:N Rate = {(Potential Yield Farmer Practice * RI)- YPFP}* N in Grain/NUE

SBNRC (YP0*RI =YPN)100 Pre (100 lbs N/ac applied preplant)

Yield Prediction

Reference Strips

• What: A high rate of N applied in, across, through, over or under each and every field

• How Much: Minimum of 125% of yield goal recommended rate, this includes residual and preplant.

• How and Where: 10 to 100 ft wide, anywhere representative.

• When: Winter crops; before or after sowing (1+ months), Summer crops; before or immediately after planting.

Reference Strips

•Are Very Visual..•BMP?•Risk Aversion?•Sales and Service?

Optical Sensors

• Numerical describe the crops BIOMASS.• DOES NOT really WORK WITH OUT A

REFERENCE..........• Multiple options

– Companies – Resolution

Optical Sensors

Sensors and No-till

• There is no cookie cutter recipe• No Text Book• Learn from others Mistakes• Adopt to your farm, soil, machinery,

management and mindset. • Do not go 100% the first year, but put out

100% of the strips. • Art

Large Scale Research Apply N-rich strip and ramp

• The applicator applies an N-rich strip (approx 179.2 Kg/Ha N) on the left 6 ft of boom.

• The right 6 ft of the boom applies an N-ramp.

Sensing

• Sense the strips prior to hollow stem

Applying top-dress

Harvest

Results

LeonardOttawa Comin-till Corn

0

3948

0102030405060

Lbs N

/ac

Leonard

Check

Farmer Practice

SBNRC

18 24 26

010203040506070

Bu/a

c

Leonard

Check

Farmer Practice

SBNRC

FP= $98.18SBNRC= $106.11Difference= $7.93

Results

RendelOttawa CoNo-till Sunflower

0

36

49

010

203040

5060

Lbs N

/ac

Rendel

Check

Farmer Practice

SBNRC

38

53 55

010203040506070

Bu/a

c

Rendel

Check

Farmer Practice

SBNRC

FP= $246.45SBNRC = $247.98Difference= $1.53

Results

0

84

39

0

20

40

60

80

100

Lbs N

/ac

Johnson

Check

Farmer Practice

SBNRC

19

3933

010203040506070

Bu/a

c

Johnson

Check

Farmer Practice

SBNRC

FP= $155.42SBNRC = $146.54Difference= $8.88

JohnsonOttawa CoNo-till SoybeanSown Nov.

Results

0

60

24

0102030405060

Lbs N

/ac

Red Barn

Check

Farmer Practice

SBNRC

4352

44

0

10

20

30

40

50

60

70Bu

/ac

Red Barn

Check

Farmer Practice

SBNRC

FP= $229.96SBNRC = $209.99Difference= $20.03

Red BarnBarber Co. KsCont Wheat

Results

0

60

70

102030405060

Lbs/

ac

Linley

Check

Farmer Practice

SBNRC

59 59 61

0

10

20

30

40

50

60

70Bu

/ac

Linley

Check

Farmer Practice

SBNRC

FP= $263.90SBNRC = $300.27Difference= $36.37

LinleyBarber Co. KsCont Wheat

Results

0

60

38

0

10

20

30

40

50

60

Lbs N

/ac

Sipel

Check

Farmer Practice

SBNRC

55

6662

0

10

20

30

40

50

60

70Bu

/ac

Sipel

Check

Farmer Practice

SBNRC

FP= $302.51SBNRC = $289.86Difference= $12.65

SipelBarber Co. KsCont Wheat

Results

0

33

59

0102030405060

Lbs N

/ac

Mach

Check

Farmer Practice

SBNRC

2429

37

010203040506070

Bu/A

c

Mach

Check

Farmer Practice

SBNRC

FP= $129.9SBNRC = $155.15Difference= $25.25

MachCanadian CoCont Wheat

Results

0

28

59

010

203040

5060

Lbs N

/ac

Bornemann

Check

Farmer Practice

SBNRC

31

4248

010203040506070

Bu/a

c

Bornemann

Check

Farmer Practice

SBNRC

FP= $202.83SBNRC = $208.21Difference= $5.38

BornemannCanadian CoCont Wheat

ResultsCheck Farmer Practice SBNRC

SiteLbs of

topdressBushel/

AcProfit/

AcLbs of

topdressBushel/

AcProfit/

AcLbs of

topdressBushel/

AcProfit/

Ac

Leonard 1 0 18 91.05 39 24 98.18 48 26 106.11

Rendel 2 0 38 191.03 36 53 246.45 49 55 247.98

Johnson 3 0 19 94.38 84 39 155.43 39 33 146.54

Red Barn 4 0 43 214.93 60 52 229.96 24 44 209.99

Linely 5 0 59 293.77 60 59 263.90 7 61 300.27

Sipel 6 0 55 276.14 60 66 302.51 38 62 289.86

Mach 7 0 24 118.33 33 29 129.90 59 37 155.15

Borne 8 0 31 152.99 28 42 196.29 59 48 209.78

Averages 36 179.08 50 46 202.83 40 46 208.21

Treatment Avg Profit Avg Yield Total N-rate (lbs/ac)

Farmer Practice 699.19 195.36 235SBNRC Flat Rate 718.68 189.73 115

RT-200 VRT 731.59 190.14 82.7N-Rich 688.53 208.88 420

Treatment Avg Profit Avg Yield Total N-rate (lbs/ac)Farmer Practice 729.70 199.92 200SBNRC Flat Rate 754.61 198.71 115

RT-200 VRT 769.43 201.13 100.4N-Rich 706.52 207.26 350

Treatment Avg Profit Avg Yield Total N-rate (lbs/ac)

Farmer Practice 825.92 223.98 200

SBNRC Flat Rate 835.21 215.80 80

RT-200 VRT 785.40 201.62 60.2

N-Rich 777.23 224.93 350

2009 Corn Trials

Thank you!!!

Email Jeff.Edwards@okstate.edu Chad.Godsey@okstate.edu with a request to be added to the list.

Sensor Based N Fertilizer Recommendation Summary 2006-2008

Location Year Sensor Yield Actual Yield Soil Test Rec. Sensor Rec. Actual N Resp. Soil Diff. Sensor Diff.Belleville 2006 95 96 40 0 0 40 0Manhattan 2006 160 155 60 33 33 27 0Partridge 2006 48 32 42 57 55 -13 2Tribune 2006 130 128 30 24 15 15 9Manhattan 2007 111 109 130 98 105 25 -7Partridge 2007 77 70 40 15 20 20 -5Tribune 2007 71 79 54 0 0 54 0Manhattan 2008 151 128 77 45 45 32 0Ottawa 2008 58 64 56 55 60 -4 -5Partridge 2008 140 123 41 30 15 26 15Average 104.1 98.4 57 35.7 34.8 22.2 0.9