Tobacco Production Update
Bob Pearce, Gary Palmer, Andy Bailey
Extension Tobacco Specialists
Kenny Seebold
Extension Plant Pathologist
Topics
• Nitrogen sources for tobacco
• Revised nitrogen rates for tobacco
• Sucker control options
– No MH options
• Variety update
• Disease update
Nitrogen Fertilizer Issues
• Economics
– Leaf prices down
– N fertilizer prices up
• Price tied to natural gas
• Transportation costs up
• Nitrosamine concerns
– Tobacco companies want less N applied
• Quality concerns
– Too little: thin body, poor yield
– Too much: delayed maturity, fat stems
Ammonium Nitrate Issues
• Most common N source for tobacco growers
• Homeland security concerns
– Can be used to make explosives
– Easy availability
• Some manufacturing plants have closed
– Tighter supplies
– Higher costs
• Sales regulations
– Permits needed to purchase large quantity?
– Some dealers reluctant to stock?
Price Per Unit of Nitrogen for Selected
Fertilizer Materials
Anhydrous Ammonia
Ammonium Nitrate
Urea
UAN Solutions
Ammonium Sufate
0.600
0.400
0.300
0.200
0.100
Year
20
02
19
99
19
96
19
93
19
90
19
87
19
84
19
81
19
78
19
75
19
72
19
69
19
66
19
63
0.000
19
60
Price ($/lb N)
0.500
Alternative N Sources
• Anhydrous ammonia (82% N)
– Lowest cost per unit of N
– Limited availability
– Special equipment needed
• Stored as liquid under pressure
• Special injectors needed
• Used in illegal meth production
– Feasible only if equipment already available
– Placement concerns
• Delayed uptake
• Phyto-toxicity if close to plants
Alternative N Sources
• Anhydrous ammonia (82% N)
– Reaction in soil
• NH3 + 2O2 → H+ + NO3- +H2O
• Same lime requirement as AN
– Suggestions for use
• Inject 6 to 8 inches deep
• 7 to 10 days before setting
Alternative N Sources
• Ammonium sulfate (21% N)
– Specialty fertilizer
• Use on acid loving crops
• Use on high pH soils
– Relatively high cost per unit N
– Limited availability
– Soil reaction
• (NH4)2SO4 + 4O2 → 4H+ +2NO3-+ SO42- + 2H2O
• 3X lime requirement of AN
– Not feasible for large scale use on tobacco
Alternative N Sources
• Urea (46% N)
– Intermediate cost
– Handling similar to ammonium nitrate
• Can impregnate some chemicals
• Same lime requirement as AN
– Converted to nitrate in the soil
• Subject to loss if surface applied
– Apply to dry soil
– Incorporate or water in
• Delayed uptake (Don’t use for sidedress)
– Feasible alternative if managed properly
Alternative N Sources
• Non Pressure Solutions (28 – 32% N)
– Intermediate cost
– Mixture of urea, ammonium nitrate, and water
– Relatively easy to transport, store, and apply
• Most nurse tanks
• Many types of sprayers
– Corrosive to equipment
– Should be incorporated
– Can be used a a carrier for spray applications
– Limited availability
– Feasible for tobacco production
Alternative N Sources
• Calcium – Ammonium Nitrate (27% N)
– Ammonium nitrate mixed with lime
• 78% ammonium nitrate
– Theoretically similar to ammonium nitrate
• Can impregnate some chemicals ?
– Relatively high cost?
– Availability?
– Limited practical experience
Alternative N Sources
• Sodium Nitrate (16% N)
• Calcium Nitrate (15.5% N)
• Sodium-Potassium Nitrate (15% N)
–
–
–
–
–
Immediate uptake (good for sidedress)
Good for low pH soils
Erratic availability
High cost
Low analysis – high transport cost
Conversion to Nitrate in soil
% of Fertilizer as NO3-N
N Source
Weeks After Application
0
3
6
Ammonium Nitrate
Anhydrous Ammonia
Urea
UAN Solution
Nitrate Sources
50
0
0
25
100
80
20
50
60
100
90
65
75
80
100
Effects of Ammonium Nitrate Application
on Soil pH
Anhydrous Ammonia, Urea, UAN solutions : similar
0N
240 lbs N
Soil pH
6.4
6.2
6
5.8
5.6
5.4
5.2
21-Aug
14-Aug
7-Aug
31-Jul
24-Jul
17-Jul
10-Jul
3-Jul
26-Jun
19-Jun
12-Jun
5-Jun
29-May
22-May
15-May
8-May
1-May
5
Effect of Liming an Acid Soil Prior to Use of
Urea and Sodium Nitrate Sources of Nitrogen
Sodium Nitrate
Urea
7
6.3
6.5
5.8
Soil pH
6
6
5.5
5.3
5.7
5
4.5
4.7
4
0
5
7.5
Tons of Lime/A
Both N sources applied at 225 lb N/A pre-plant.
Soil pH (water) measured at midseason of each year. Soil pH before liming was 5.4.
Effect of Liming an Acid Soil Prior to Use of
Urea and Sodium Nitrate Sources of Nitrogen
Sodium Nitrate
Yield lb/a
3000
2765
2800
2612
2600
2772
2750
2647
2400
2200
2358
2000
0
5
Tons of Lime/A
Both N sources applied at 225 lb N/A pre-plant.
7.5
Urea
Nitrogen Source Study
Harrison Co. – Keith Smith Farm
3000
2846
2889
2878
2867
178
323
313
323
342
68
1058
1169
1086
1007
2500
Yield lb/a
2000
148
1500
1000
187
1040
928
1030
1039
425
478
438
480
87
AN
U
CN
SN
LSD
500
0
Flyings
Lugs
Leaf
Tips
Total
100 units AN Broadcast Sidedressed with 170 units each,
AN = Ammonium Nitrate, U= Urea, CN = Calcium Nitrate, SN = Sodium Nitrate
Conventional Fertility Trial
Monroe Co. – Al Pedigo Farm
2500
1847
2169
1977
1926
1939
657
540
544
850
888
850
469
498
544
450 AN +
645 CN
450 AN +
625 SN
450 AN +
217 U
400
2000
Yield lb/a
662
1500
1000
515
976
829
110
241
500
532
502
135
0
Broadcast
Sidedress
Flyings
450 AN +
300 AN
Lugs
750 AN +
Leaf
Total
LSD
Number = lbs of product, AN = Ammonium Nitrate, CN
= Calcium Nitrate, SN = Sodium Nitrate, U= Urea
No-till Fertility Trial
Monroe Co. – Al Pedigo Farm
3000
2404
2567
2654
705
817
2348
2425
295
Yield lb/a
2500
2000
735
710
725
1062
1062
577
638
450 AN +
625 SN
450 AN +
217 U
119
1500
1113
1000
1082
500
750
587
1164
674
181
102
0
Broadcast
Sidedress
Flyings
450 AN +
300 AN
Lugs
750 AN +
Leaf
Total
450 AN +
645 CN
LSD
Number = lbs of product, AN = Ammonium Nitrate, CN
= Calcium Nitrate, SN = Sodium Nitrate, U= Urea
Effects of Sidedressing Different
Sources of Nitrogen on Burley Yield
Elliot Co. – Tracy D. Kitchen Farm
2500
2000
2229
1942
482
2130
2108
436
486
905
873
Yield lb/a
442
1500
991
815
1000
500
757
686
790
750
300 Am Nitrate
222 Urea
645 Ca Nitrate
625 Na Nitrate
0
Flyings
Lugs
Leaf
450 Ammonium Nitrate Broadcast followed by 100 lb/a of Nitrogen Sidedressed.
Am = Ammonium, Ca = Calcium & Na = Sodium. There were no significant differences.
Effect of Nitrogen Source on Burley Yield
Marshall Co. – Glen Thompson Farm
3000
2579
2605
2650
2684
225
Yield lb/a
2500
2000
1114
1176
1303
1203
310
1092
1048
970
1084
223
373
381
377
397
57
Am Nitrate
Urea
Ca Nitrate
Na Nitrate
LSD
1500
1000
500
0
FLYINGS
LUGS
LEAF
150 units Urea Broadcast Sidedressed with 100 units each at sidedressing,
Ca = Calcium and Na = Sodium
Revised Nitrogen Rates
• AGR-1 will have a new table for N on tobacco
–
–
–
–
–
Based on crop history (same as old)
No additional N for continuous tobacco
Soil drainage formally considered
“Typical” recommendation 50 lbs. N/A less
Rate lower if sidedressing is practiced
• Economically sound recommendations
• Reduce incidence of over-application
Revised Nitrogen Recommendations for
Burley and Dark Tobacco.
Well Drained
Soil
Moderately Well
Drained Soil
------------Lb N/A-----------Low N levels: following tobacco
or row crops
225-250
250-275
Medium N levels: first-year
tobacco following a grass or
grass-legume sod
200-225
225-250
High N levels: first-year tobacco
following legume sod or
legume cover crop
150-175
175-200
Effects of Nitrogen Rates on Burley Tobacco at
Spindletop Farm (Maury Silt Loam)
1991
1992
4000
Yield lb/a
3500
3000
2500
2000
0
50
100
150
200
250
300
N rate (lb/a)
– MacKown, Sutton and Crafts-Brander – 1994
350
400
Nrate across location years and method
4500
2
y = -0.0061x + 4.0053x + 2180.2
Leaf Yield (lbs. A)
4000
2
R = 0.1249
3500
3000
2500
2000
1500
1000
500
0
0
50
100
150
200
N rate (lbs./A)
250
300
350
400
Effect of N rate and method of
application on burley tobacco yield.
Poly. (Preplant)
Poly. (Split )
Yield (lbs/A)
3000
2750
2500
2250
2000
0
50
100
150
200
250
300
350
400
N rate (lbs/A)
If 1/3 or more is sidedressed reduce total amount of N by
15 to 25 lbs./A
Summary
• Encourage growers to compare costs and consider
alternative N sources
• Revised N rates
–
–
–
–
Rates lowered by about 50 lbs./A
Will not significantly lower yield
Improved quality
Promotes desired chemical properties
• Reduce rate if sidedressing is practiced