Evaluation of the Yield Potential Evaluation of the Yield Potential Based NFOA for CottonBased NFOA for Cotton

D. Brian ArnallD. Brian Arnall

Oklahoma State UniversityOklahoma State University

W. Raun, J. Solie, M. Stone, R. Taylor, J.C. BanksW. Raun, J. Solie, M. Stone, R. Taylor, J.C. BanksO. Walsh, D. Edmonds, C. Daft, B. England,O. Walsh, D. Edmonds, C. Daft, B. England,

Y. Kanke, B. Desta Y. Kanke, B. Desta

Sensor Based Nitrogen Rate Sensor Based Nitrogen Rate CalculatorCalculator

What is needed.What is needed.Yield Prediction ModelYield Prediction Model

Response IndexResponse Index

Nitrogen RemovalNitrogen Removal

Nitrogen Use Efficiency.Nitrogen Use Efficiency.

N Rate = (YP0 * RI – YP0) * %N / N Rate = (YP0 * RI – YP0) * %N / EfficiencyEfficiency

The Experimental SitesThe Experimental Sites20062006– 1 Site: Lake Carl Blackwell (LCB)1 Site: Lake Carl Blackwell (LCB)

2-4.D2-4.DLate Season StressLate Season Stress

20072007– 3 sites: LCB YP, Altus 439, and Altus N study3 sites: LCB YP, Altus 439, and Altus N study

NDVI collected over and between rowsNDVI collected over and between rows

20082008– 4 sites: LCB Irrigated YP, LCB Dryland N 4 sites: LCB Irrigated YP, LCB Dryland N

study, Altus 439, and Altus N studystudy, Altus 439, and Altus N study

Yield Potential ModelYield Potential Model

Why use YP.Why use YP.– Nitrogen is a model nutrient and according to Nitrogen is a model nutrient and according to

Bray need is yield dependent.Bray need is yield dependent.

Using NDVI as a function of GDD. Using NDVI as a function of GDD. Days from Planting or Cumulative GDDDays from Planting or Cumulative GDD

43 Locations, 1998-2006

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009 0.01

INSEY

Gra

in y

ield

, M

g/h

a

PKNP 1998PKSN 1998TPSN 1998PKNP 1999222 1999301 1999EFAA 1999801 1999502 1999PKNP 2000222 2000301 2000EFAA 2000801 2000502 2000HNAA 2000PKNP 2001222 2001301 2001EFAA 2001801 2001PKNP 2002222 2002301 2002EFAA 2002801 2002HNAA 2002502 2003222 2003EFAA 2003PKNP 2004222 2004301 2004502 200420052006

YP0 = 0.409e258.2 INSEY R2=0.50

YP0 + 1Std Dev = 0.590 e258.2 INSEY

Units: biomass, kg/ha/day, where GDD>0

Winter WheatWinter Wheat

Yield Potential ModelYield Potential Model

INSEY DFPINSEY DFP

Relationship between in season estimate of yield (INSEY) computed from NDVIRelationship between in season estimate of yield (INSEY) computed from NDVI

readings of cotton collected between 60-80 days after planting, divided by thereadings of cotton collected between 60-80 days after planting, divided by the

number of days of planting to sensing, and measured lint yield from all site years. number of days of planting to sensing, and measured lint yield from all site years.

Where YP0 = yield potential; YP0 calculated = the mean + one standard deviation. Where YP0 = yield potential; YP0 calculated = the mean + one standard deviation.

YP0 = 27.04e303.34x

y = 20.331e303.34x

r2 = 0.46

0

400

800

1200

1600

0.008 0.009 0.010 0.011 0.012 0.013 0.014

DFP INSEY (NDVI / days from planting to sensing)

Lin

t Y

ield

(kg

ha

-1)

LCB06-64DFP

LCB06-66DFP

LCB06-79DFP

LCB07-70DFP

LCB07-77DFP

SWR-60DFP

INSEY Cum GDDINSEY Cum GDD

YPO = 235.96e2216.2x

y = 177.41e2216.2x

r2 = 0.69

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1600

0.000 0.000 0.001 0.001 0.001

CumINSEY (NDVI / Cumm GDD)

Lin

t Y

ield

(k

g h

a-1

)

LCB06-886CummGDD

LCB06-949CummGDD

LCB06-1161CummGDD

LCB06-1215CummGDD

LCB07-1015CummGDD

LCB07-1152CummGDD

LCB07-1262CummGDD

SWR-846CummGDD

SWR-999CummGDD

Relationship between in season estimate of yield (Cum INSEY) computed fromRelationship between in season estimate of yield (Cum INSEY) computed fromNDVI readings of cotton at growth stages from square to peak bloom (800-1300NDVI readings of cotton at growth stages from square to peak bloom (800-1300Cumm GDD), divided by the number of days of planting to sensing, and measuredCumm GDD), divided by the number of days of planting to sensing, and measuredlint yield from all site years. Where YP0 = yield potential; YP0 calculated = thelint yield from all site years. Where YP0 = yield potential; YP0 calculated = themean + one standard deviation mean + one standard deviation

NDVI Over TimeNDVI Over Time

y = -0.0003x2 + 0.044x - 0.8865

r2 = 0.70

0.0

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1.0

30 40 50 60 70 80 90 100

Days from Planting to Sensing

ND

VI

The trend of NDVI values as days from planting to sensing increases. The trend of NDVI values as days from planting to sensing increases.

Response IndexResponse Index

Dr. JohnsonDr. Johnson

Response to added fertilizer nitrogenResponse to added fertilizer nitrogen

RIRINDVINDVI

– NDVI of the N-Rich Strip / Farmer PracticeNDVI of the N-Rich Strip / Farmer Practice

RIRIHarvestHarvest

– Yield of the N-Rich Strip / Farmer PracticeYield of the N-Rich Strip / Farmer Practice

RI Harvest and RI NDVIRI Harvest and RI NDVI

Relationship between the response index measured in season, (NDVI of fertilizedRelationship between the response index measured in season, (NDVI of fertilizedplot / NDVI of check plot) from readings of cotton at growth stages from 60 to 80plot / NDVI of check plot) from readings of cotton at growth stages from 60 to 80days after planting, and measured lint yield and the response index measured atdays after planting, and measured lint yield and the response index measured atharvest (yield of fertilized plot / yield of check plot) from all site years. harvest (yield of fertilized plot / yield of check plot) from all site years.

y = 1.8579x - 0.932

r2 = 0.39

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0.5

1.0

1.5

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0.5 0.8 1.0 1.3 1.5

RI NDVI

RI H

arve

st

LCB06-64DFP

LCB06-66DFP

LCB06-79DFP

LCB07-70DFP

LCB07-77DFP

SWR-60DFP

Nitrogen Use and UptakeNitrogen Use and Uptake

Research from different parts of the Cotton Research from different parts of the Cotton Belt suggests that high-yielding cotton Belt suggests that high-yielding cotton crops contain about 50-55 lbs. N/bale crops contain about 50-55 lbs. N/bale – (Basset et al., 1970; Mullins & Burmester, 1990; Unruh and Silvertooth, 1996).  Cotton Corp(Basset et al., 1970; Mullins & Burmester, 1990; Unruh and Silvertooth, 1996).  Cotton Corp

OSU Recommends 27 kg / bale (60 lbs N)OSU Recommends 27 kg / bale (60 lbs N)Equivalent to .125 kg N / kg Lint, 12.5%Equivalent to .125 kg N / kg Lint, 12.5%

N ComponentsN Components

If all plant components are accounted for in the If all plant components are accounted for in the algorithm, this results in 146.39 g N kg-1 lint algorithm, this results in 146.39 g N kg-1 lint (70.267 lbs N bale-1).(70.267 lbs N bale-1).Higher than the values recorded as optimum N Higher than the values recorded as optimum N rates for cotton grown in Oklahoma of 83.0 g N rates for cotton grown in Oklahoma of 83.0 g N kg-1 lint. The kg-1 lint. The Girma et al. (2007a) data closely fit the value of Girma et al. (2007a) data closely fit the value of 90 g N kg-1 lint which was calculated from 90 g N kg-1 lint which was calculated from removal of lint and seed. removal of lint and seed. Not known if using the N content of only the lint Not known if using the N content of only the lint and seed is adequate and seed is adequate Or if it will be necessary burs, leaves or stems. Or if it will be necessary burs, leaves or stems.

Nitrogen Use and UptakeNitrogen Use and Uptake

Maximum N uptake occurred between 49 and 71 Maximum N uptake occurred between 49 and 71 days after planting and was 2.9 and 4.3 kg hadays after planting and was 2.9 and 4.3 kg ha -1-1 dayday-1-1 for cotton receiving 84 and 168 kg N ha for cotton receiving 84 and 168 kg N ha -1-1, , respectively.respectively.– Boquet, D.J., and G.A. Breitenbeck. 2000. Nitrogen rate effect on partitioning of nitrogen Boquet, D.J., and G.A. Breitenbeck. 2000. Nitrogen rate effect on partitioning of nitrogen

and dry matter by cotton. Crop. Sci., Vol 40 pg 1685-1693and dry matter by cotton. Crop. Sci., Vol 40 pg 1685-1693

Very little literature.Very little literature.

NUE of 50%. NUE of 50%.

SBNRC AlgorithmSBNRC Algorithm

N Rate = (YP0 * RI – YP0) * %N / NUEN Rate = (YP0 * RI – YP0) * %N / NUE

potential cotton lint yield, kg/ha = 235.96 e potential cotton lint yield, kg/ha = 235.96 e 2216.2 * INSEY 2216.2 * INSEY cotton lint yield, kg/ha = 177.41 e 2216.2 * cotton lint yield, kg/ha = 177.41 e 2216.2 * INSEYINSEYWhere:Where:YP0 = 235.96 e 2216.2 * INSEYYP0 = 235.96 e 2216.2 * INSEYRI = 1.8579 * RINDVI – 0.932RI = 1.8579 * RINDVI – 0.932%N = 0.09%N = 0.09NUE = 0.50NUE = 0.50

2008 Sensing2008 SensingLCB Irrigated

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1 2 3 4 5 6 7 8 1 2 3 4

Treatment

YP

0 (

Ba

les

/ac

)

730 GDD

832 GDD

943 GDD

1148 GDD

1300 GDD

2008 Sensing2008 Sensing

LCB Dryland

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6

1 2 3 4 5 6 7 8 8 9

Treatment

YP

0 (B

ales

/ac) 700 GDD

832 GDD

943 GDD

1148 GDD

1300 GDD

The UnknownThe Unknown

Can Cotton “Catch-up” once it is behind?Can Cotton “Catch-up” once it is behind?

What should the level of preplant N be?What should the level of preplant N be?

What is the application window?What is the application window?

Plant Growth Regulators.Plant Growth Regulators.

Thank youThank you

Any Questions??????