development of cotton n fertilization algorithms, southern usa
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Development of Cotton N Fertilization Algorithms, Southern USA. Kevin Bronson Brenda Tubana Brian Arnall. Improved Strategies for Nitrogen Management in Subsurface Drip Irrigated Cotton. Kevin F. Bronson, Adi Malapati Jason Nusz , Jeff Johnson. - PowerPoint PPT PresentationTRANSCRIPT
Development of Cotton N Fertilization Algorithms, Southern USA
Kevin BronsonBrenda Tubana
Brian Arnall
Kevin F. Bronson, Adi Malapati Jason Nusz, Jeff Johnson
Texas A & M AgriLife Res, and Texas Tech Univ. Lubbock, TX
Improved Strategies for Nitrogen Management in Subsurface Drip Irrigated
Cotton
Treatments • Soil test based N mgt (STB) 32-0-0 injected early square to mid bloom
for 2.5 bale/ac yield goal (125 lb N/ac – 0-24 in soil test NO3-N – irrigation water NO3)
• 0.5 X Soil test based (0.5 STB)
• 1.5 X Soil test based (1.5 STB)
• Zero-N (1 plot/station/rep)
• Reflectance-based mgt 1: initially 0.5 STB N rate, N injection rate adjusted upwards to STB rate when NDVI REF1 is statistically < NDVI REF1.
• Reflectance-based mgt 2 : initially STB N rate, N injection rate adjusted upwards to 1.5 STB rate when NDVI REF2 is statistically < NDVI 1.5 STB.
First open boll biomass, N accumulation, N fertilizer recovery efficiency, seed and lint yields as affected by nitrogen management, Lubbock, TX, 2007.
N treatment N fertilizer injecteda
Total N uptake
Recovery efficiency Biomass Seed yield Lint
yield
---- lb N/ac ----- % --------------- lb/ac --------------
1.5*STB 120 - - - 2379 a 1347 a
Refl- strategy 2 90 131 a* 62 a 7666 a 2253 a 1330 a
STB 80 128 a 65 a 7704 a 2241 a 1326 a
Refl.strategy 1 62 120 a 72 a 7561 a 2350 a 1372 a
0.5*STB 40 - - - 2270 a 1365 a
Zero-N 0 76 - 5362 1692 1062 a Injected from 11 July to 11 August*Means in a column followed by the same letter are not significantly different at P = 0.05
N treatment N fertilizer injected1
Total N uptake
Recovery efficiency Biomass Seed
yieldLint yield
--------- lb N/ac ------ % --------------- lb/ac -------------
1.5*STB 94 138 a 75 a 7993 a 2553 a 1532 a
Refl.strategy 2 62 - - - 2572 a 1586 a
STB 62 130 a 101 a 7546 a 2455 a 1495 a
Refl.strategy 1 46 110 b 94 a 6587 b 2542 a 1538 a
0.5*STB 31 - - - 2129 b 1283 b
Zero-N 0 67 - 4968 1640 1006
First open boll biomass, N accumulation, N fertilizer recovery efficiency, seed and lint yields as affected by nitrogen management, Lubbock, TX, 2008.
a Injected from 26 June to 16 July and 5 to 8 August*Means in a column followed by the same letter are not significantly different at P = 0.05
N treatmentN
fertilizer injected1
Total N uptake
Recovery Efficiency
Biomass
Seed yield
Lint yield
---------- lb N/ac ------- % --------------- lb/ac
-------------
1.5*STB 72 124 a 47 a 7761 a 2526 a 1527 a
Refl.strategy 2 48 - - - 2487 ab 1509 a
STB 48 114 a 49 a 7670 a 2471 ab 1522 a
Refl.strategy 1 24 109 a 77a 8058 a 2581 a 1610 a
0.5*STB 24 - - - 2326 b 1487 a
Zero-N 0 90 - 6962 2029 1336
First open boll biomass, N accumulation, N fertilizer recovery efficiency, seed and lint yields as affected by nitrogen management, Lubbock, TX, 2009
Summary of three years of Refl. Strategy 1 N fertilizer management in SDI cotton, Lubbock, TX, 2007-2009
Units 2007 2008 2009
0-24 inch NO3 lb /ac 17 30 18
Starter N fertilizer lb N/ac 0 10 22
Irrigation NO3 lb N/ac 20 30 22
Injected fertilizer lb N/ac 62 46 24
Recovery efficiency % 72 94 77
Lint yield lb /ac 1372 1538 1610
Summary of three years of soil test based strategy for N fertilizer management in SDI cotton, Lubbock, TX, 2007-2009
Units 2007 2008 2009
0-24 inch NO3 lb /ac 24 35 21
Starter N fertilizer lb N/ac 0 10 22
Irrigation NO3 lb N/ac 20 30 22
Injected fertilizer lb N/ac 80 62 48
Recovery efficiency % 65 101 49
Lint yield lb /ac 1326 1495 1522
Conclusions
• Recovery efficiency of daily injection of N between early square and mid bloom was 62 to 94 %.
• Reflectance-based N management strategy1 saved 22, 26, and 50 % N compared to soil test based management during 2007, 2008, and 2009, respectively.
• EONRs ranged from 22 to 68 lb N/ac for lint.
LSU
• 2009– NDVI and Yield best correlated at later stage. 4
weeks after first bloom – RI NDVI and RI yield best correlated at 2 weeks
after first bloom• Tested 08 algorithm
Table 1. Lint grain yield and optimal nitrogen rates estimated using linear-plateau model and sensor-based N decision tool
Site N Response Trial* Sensor-Based, Split N Rate†
lbs/ac Lint Yield‡
lbs/ac Total N Rate
lbs/ac Lint Yield
lbs/ac Commerce silty clay loam 110 1257 120 (45-75) 1045 Sharkey clay 112 902 98 (0-98) 802 Gigger silt loam 90 1220 64 (45-19) 1056
*N response trial – constituted the plots that received step-wise increment of N from 0 to 150 lbs/ac. † N rate – optimal N rate estimated by non-linear regression analysis (linear-plateau model). ‡ Lint Yield – maximum yield that can be attained with the corresponding optimal N rate. Table 2. Lint yield applied with commonly-applied flat N rate and rates recommended
by sensor-based N decision tool . Site Scheme N Application Rate
lbs/ac Lint Yield
lbs/ac Split Rate Total
Sharkey clay‡ Flat 0-60 60 540 Sensor 0-98 98 802 Commerce silty clay loam Flat 45-45 90 1143 Sensor 45-75 120 1045 Gigger silt loam Flat 45-45 91 1182 Sensor 45-16 64 1056 ‡ - N was not applied at planting.
Ok State
• 4 years of Data– Stillwater and Altus
• NDVI and Cumulative GDD’s • First White Flower• Environment
Yield Prediction
0.0003 0.0004 0.0005 0.0006 0.0007 0.0008 0.0009 0.00100
500
1000
1500
2000
2500
3000
f(x) = 174.120525260041 exp( 3668.12834211478 x )R² = 0.508564742494368
f(x) = 20.7567448124509 exp( 4818.43614872994 x )R² = 0.824581137299074
LCB
YP Models
0.0003 0.0004 0.0005 0.0006 0.00070
500
1000
1500
2000
2500
f(x) = 231.579600000001 exp( 3668.09999999999 x )
f(x) = 174.120525260042 exp( 3668.12834211477 x )R² = 0.508564742494366
South West
INSEY (NDVI / Cum GDD)
Lint
Yie
ld K
g ha
0.0004 0.0005 0.0006 0.0007 0.0008 0.00090
500
1000
1500
2000
2500
f(x) = 29.31852 exp( 4725.79999999999 x )
f(x) = 22.043707195574 exp( 4725.78765123985 x )R² = 0.811253945853535
North Central
INSEY (NDVI / Cum GDD)
Lint
Yie
ld K
g ha
Response Index
0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.600.0
0.5
1.0
1.5
2.0
2.5
3.0
LCBAltus
RI NDVI
RI H
arve
st
2010
• Continue Catch-up and YP trials (long-term).• SBNRC trts. • Altus
– 30 lb pre 62 lbs applied (42-96)– 60 lb pre 26 lbs applied (17-42)
• LCB – 0 lb pre 28 lbs applied ( 17-45)– 40 lb pre 16 lbs applied (4-27)
Thank you