Transcript Use of By-Plot CV’s for Refining Mid
Evaluation of the Yield Potential Based NFOA for Cotton
D. Brian Arnall
Oklahoma State University W. Raun, J. Solie, M. Stone, R. Taylor, J.C. Banks O. Walsh, D. Edmonds, C. Daft, B. England, Y. Kanke, B. Desta
Sensor Based Nitrogen Rate Calculator What is needed.
Yield Prediction Model Response Index Nitrogen Removal Nitrogen Use Efficiency.
N Rate = (YP0 * RI – YP0) * %N / Efficiency
The Experimental Sites
2006 –
1 Site: Lake Carl Blackwell (LCB) 2-4.D
Late Season Stress
2007 –
3 sites: LCB YP, Altus 439, and Altus N study NDVI collected over and between rows
2008 –
4 sites: LCB Irrigated YP, LCB Dryland N study, Altus 439, and Altus N study
Yield Potential Model
Why use YP.
– Nitrogen is a model nutrient and according to Bray need is yield dependent.
Using NDVI as a function of GDD. Days from Planting or Cumulative GDD
Yield Potential Model
8.0
7.0
6.0
43 Locations, 1998-2006
YP 0 = 0.409e
258.2 INSEY R 2 =0.50
YP 0 + 1Std Dev = 0.590 e 258.2 INSEY 5.0
4.0
Winter Wheat
3.0
2.0
1.0
0.0
0 0.001
0.002
0.003
0.004
0.005
INSEY
0.006
0.007
0.008
0.009
0.01
Units: biomass, kg/ha/day, where GDD>0 PKNP 1998 PKSN 1998 TPSN 1998 PKNP 1999 222 1999 301 1999 EFAA 1999 801 1999 502 1999 PKNP 2000 222 2000 301 2000 EFAA 2000 801 2000 502 2000 HNAA 2000 PKNP 2001 222 2001 301 2001 EFAA 2001 801 2001 PKNP 2002 222 2002 301 2002 EFAA 2002 801 2002 HNAA 2002 502 2003 222 2003 EFAA 2003 PKNP 2004 222 2004 301 2004 502 2004 2005 2006
INSEY DFP
1600 1200 y = 20.331e
303.34x
r 2 = 0.46
YP0 = 27.04e
303.34x
800 400 LCB06-64DFP LCB06-66DFP LCB06-79DFP LCB07-70DFP LCB07-77DFP SWR-60DFP 0 0.008
0.009
0.010
0.011
0.012
0.013
DFP INSEY (NDVI / days from planting to sensing) 0.014
Relationship between in season estimate of yield (INSEY) computed from NDVI readings 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. Where YP0 = yield potential; YP0 calculated = the mean + one standard deviation.
INSEY Cum GDD
1600 1200 y = 177.41e
2216.2x
r 2 = 0.69
YPO = 235.96e
2216.2x
800 400 LCB06-886CummGDD LCB06-949CummGDD LCB06-1161CummGDD LCB06-1215CummGDD LCB07-1015CummGDD LCB07-1152CummGDD LCB07-1262CummGDD SWR-846CummGDD SWR-999CummGDD 0 0.000
0.000
0.001
0.001
CumINSEY (NDVI / Cumm GDD) 0.001
Relationship between in season estimate of yield (Cum INSEY) computed from NDVI readings of cotton at growth stages from square to peak bloom (800-1300 Cumm GDD), divided by the 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
NDVI Over Time
1.0
0.8
0.6
0.4
0.2
0.0
30 y = -0.0003x
2 + 0.044x - 0.8865
r 2 = 0.70
40 50 60 70 Days from Planting to Sensing 80 90 The trend of NDVI values as days from planting to sensing increases. 100
Response Index
Dr. Johnson Response to added fertilizer nitrogen RI NDVI – NDVI of the N-Rich Strip / Farmer Practice RI Harvest – Yield of the N-Rich Strip / Farmer Practice
2.0
RI Harvest and RI NDVI
y = 1.8579x - 0.932
r 2 = 0.39
1.5
1.0
0.5
LCB06-64DFP LCB06-66DFP LCB06-79DFP LCB07-70DFP LCB07-77DFP SWR-60DFP 0.0
0.5
0.8
1.0
RI NDVI 1.3
1.5
Relationship between the response index measured in season, (NDVI of fertilized plot / NDVI of check plot) from readings of cotton at growth stages from 60 to 80 days after planting, and measured lint yield and the response index measured at harvest (yield of fertilized plot / yield of check plot) from all site years.
Nitrogen Use and Uptake
Research from different parts of the Cotton Belt suggests that high-yielding cotton crops contain about 50-55 lbs. N/bale – (Basset et al., 1970; Mullins & Burmester, 1990; Unruh and Silvertooth, 1996). Cotton Corp OSU Recommends 27 kg / bale (60 lbs N) Equivalent to .125 kg N / kg Lint, 12.5%
N Components
If all plant components are accounted for in the algorithm, this results in 146.39 g N kg-1 lint (70.267 lbs N bale-1).
Higher than the values recorded as optimum N rates for cotton grown in Oklahoma of 83.0 g N kg-1 lint. The Girma et al. (2007a) data closely fit the value of 90 g N kg-1 lint which was calculated from removal of lint and seed. Not known if using the N content of only the lint and seed is adequate Or if it will be necessary burs, leaves or stems.
Nitrogen Use and Uptake
Maximum N uptake occurred between 49 and 71 days after planting and was 2.9 and 4.3 kg ha -1 day -1 for cotton receiving 84 and 168 kg N ha -1 , respectively.
– 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 1685-1693 Very little literature.
NUE of 50%.
SBNRC Algorithm
N Rate = (YP0 * RI – YP0) * %N / NUE potential cotton lint yield, kg/ha = 235.96 e 2216.2 * INSEY cotton lint yield, kg/ha = 177.41 e 2216.2 * INSEY Where: YP0 = 235.96 e 2216.2 * INSEY RI = 1.8579 * RINDVI – 0.932
%N = 0.09
NUE = 0.50
2008 Sensing
LCB Irrigated 2 1 0 7 4 3 6 5 1 2 3 4 5 6 7 Treatment 8 1 2 3 4 730 GDD 832 GDD 943 GDD 1148 GDD 1300 GDD
2008 Sensing
LCB Dryland 1 0 3 2 6 5 4 1 2 3 4 5 6 Treatment 7 8 8 9 700 GDD 832 GDD 943 GDD 1148 GDD 1300 GDD
The Unknown
Can Cotton “Catch-up” once it is behind?
What should the level of preplant N be?
What is the application window?
Plant Growth Regulators.