Sulfur Fertility for Barley Production in the Mid-Atlantic
Mark S. Reiter1,2, Wade E. Thomason2, David Moore3, and Keith Balderson4
1
Virginia Tech Eastern Shore Agricultural Research and Extension Center (AREC)
2
Department of Crop and Soil Environmental Sciences, Virginia Tech
3
Middlesex County, Virginia Cooperative Extension
4
Essex County, Virginia Cooperative Extension
INTERPRETIVE SUMMARY
Virginia consistently produces approximately 72,000 acres of barley per year. As with any grain,
sulfur (S) fertility recommendations need to be established to ensure adequate supply for
producing high yields. Sulfur fertilizer applications are an important consideration for farmers in
the Mid-Atlantic utilizing sandy loam soils as air quality improvement has reduce amounts of
“free” fertility. We conducted a S source × S rate study to determine if S fertilizer applications
were necessary. In this study, up to 21 bu/acre yield increases were observed when comparing
treatments with and without S fertilizer additions. SulfN26 consistently gave highest yields with
S rates of 10 lbs/acre being necessary for highest yields.
INTRODUCTION
Sulfur deficiency in grain production is on the rise in the United States due to decreased
atmospheric deposition from a reduction in air pollution and acid rain (USEPA, 2012).
According to the USEPA (2012), sulfate deposition in Virginia has decreased approximately 10
lbs/acre from 1990 to 2006. While a reduction in air pollution is positive environmentally,
agronomic production systems are increasingly seeing a need for sulfur fertilizer additions to
maximize yield and overall production. Virginia consistently produces approximately 72,000
acres per year with an average yield of 79 bu/acre (5-year average; USDA-NASS, 2013). Sulfur
fertility recommendations need to be established to ensure that S is not the most limiting nutrient
in our Mid-Atlantic production systems. According to the International Plant Nutrition Institute,
a 170 bu/ac barley yield requires 32 lbs. S/acre (0.1 lb. S/bu is taken up in straw and 0.09 lb.
S/bu in barley grain) (IPNI, 2003).
MATERIALS AND METHODS
Locations:
1. Accomack County, Eastern Shore AREC
2. Essex County, Farmer production field
Soil: 1. Eastern Shore AREC: Bojac sandy loam (65% sand, 25% silt, 10% clay; 0.75% organic
matter).
2. Essex County: Suffolk sandy loam (68% sand, 20% silt, 12% clay; 1.25% organic
matter).
Climate: 1. Eastern Shore AREC: Mean annual precipitation = 43 inches/year; Mean annual
temperature = 59°F; Frost free days = 210 days.
2. Essex County: Mean annual precipitation = 46 inches/year; Mean annual
temperature = 59°F; Frost free days = 210 days.
Sulfur: 1. Eastern Shore AREC: 7 ppm S; Mehlich-3 extractable.
2. Middle Peninsula: 8 ppm S; Mehlich-3 extractable.
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Water Availability: Natural rainfall.
Sulfur is relatively mobile in the soil system; therefore, S was incorporated with N fertilizer to
reduce chances of leaching and other environmental losses. Nitrogen (N) sources included
SulfN26 (ammonium sulfate nitrate; 26-0-0-14S), SulfN (ammonium sulfate; 21-0-0-24S), and
liquid urea-ammonium nitrate (UAN; 32-0-0-0S). Sulfur treatments were applied via SulfN26,
SulfN, and UAN + ammonium thiosulfate (AT; 12-0-0-26S). One treatment of UAN was
included with no S to test for S response. Similarly, one treatment received no N to test for N
response. Ammonium nitrate was used to balance N in the SulfN treatments. Granular fertilizers
were weighed out and broadcast applied by hand to plots. Liquid UAN was applied with a
calibrated backpack CO2 sprayer and broadcast nozzles.
The current N management regime recommended for Virginia barley production includes tiller
counts and tissue tests at Zadok’s growth stages (GS) 25 and 30 (Alley et. al., 2009), not to
exceed a total of 100 lbs. N/acre in two Spring split applications. For this study, we applied ½ of
the N and S at GS 25 and the remaining ½ at GS 30. The following treatment structure was used:
Source
N and S Check
Nitrogen Check
Nitrogen Check
Nitrogen Check
Sulfur Check (UAN)
SULF-N
SULF-N
SULF-N
SULF-N-26
SULF-N-26
SULF-N-26
UAN+AT
UAN+AT
UAN+AT
Application Timing
GS 25
GS 30
Total
-------------------lbs. S/ac-------------------0
0
0
5
5
10
10
10
20
15
15
30
0
0
0
5
5
10
10
10
20
15
15
30
5
5
10
10
10
20
15
15
30
5
5
10
10
10
20
15
15
30
Total
--lbs. N/ac-0
0
0
0
100
100
100
100
100
100
100
100
100
100
Phosphorus, potassium, other macro and micronutrients, and production practices were based on
Virginia Cooperative Extension Recommendations. All plots were replicated 4 times. No-tilled
‘Thoroughbred’ barley was planted in 10 feet wide by 20 feet long plots. Statistically the
experiment was a randomized complete block design arranged in a factorial arrangement of 3 S
sources (SulfN, SulfN26, and UAN+AT) × 3 S rates (10, 20, and 30 lbs S/ac) + a 0-S check + a 0
S and N check + a 0-N check with S applied at 10, 20, and 30 lbs S/ac = 14 treatments × 4
replications = 56 plots per location. Whole plant aboveground biomass was taken at 50%
heading to be analyzed for total S and total N concentration using dry combustion on an
Elementar Vario EL Cube CNS analyzer. Biomass multiplied by S and N concentration will give
relative S and N fertilizer uptake for fertilizer use efficiency calculations. The middle 5 feet of
each plot was harvested with a plot combine. Yield was corrected to a moisture concentration of
14.5% for a standard bushel weight of 48 lbs grain/bushel.
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RESULTS AND DISCUSSION
Yield S source × S rate interactions were not significant at either location in 2012. Therefore, all
data presented is presented as a main effect and is averaged over the other factor. For this report,
only yield data will be discussed as tissue analysis is still progressing. All plant tissue is dried,
weighed, ground, and is awaiting combustion.
In Essex County, SulfN26 yielded higher than SulfN (82.6 vs. 69.2 bu/acre, respectively; LSD0.10
= 11.1 bu/acre); averaged across S rates (Table 1). Yields did indicate a positive response to S
fertility as 0-S plots that received 100 lbs N/acre only yielded 61.4 bu/acre. Fertilizing with
SulfN26 yielded a 21.2 bu/acre yield advantage. Contrary to previous years and the Essex
location, differing results occurred on the Eastern Shore (Table 2). Overall, there was no yield
advantage to S fertility as the no-S treatments averaged 74.3 bu/acre. SulfN26 had higher yields
(76.4 bu/acre) than SulfN (71.5 bu acre; LSD0.10 = 4.7 bu/acre). Plots did show a yield response
to N fertilizer with 0-N plots that received the full sulfur treatments averaging 25.9 bu/acre and
check plots that received 0-N and 0-S yielding 22.7 bu/acre (Table 2). Generally, there were no
meaningful differences between test weight or grain moisture at harvest when comparing S
fertilizer sources (Table 1 and 2).
Similar to data from 2011, S rates in Essex County indicated that 10 lbs S/acre was sufficient for
reaching maximum yields as compared to the 0-S fertilizer treatment (73.1 vs. 61.4 bu/acre,
respectively; LSD0.10 = 9.6 bu/acre); averaged across S sources (Table 3). This equates to an 11.7
bu/acre yield advantage by applying 10 lbs. S/acre. Dissimilar to 2011 and Essex plots, Eastern
Shore treatments had no yield advantage to S fertility (Table 4). Neither test weight nor grain
moisture at harvest had any meaningful differences between treatments (Tables 3 and 4).
CONCLUSION
Sulfur fertilizer applications are an important consideration for farmers in the Mid-Atlantic
utilizing sandy loam soils. Of the two locations, one location had significant yield responses to S
fertilizer additions. SulfN26 gave highest yields with S rates of 10 lbs/acre being necessary for
optimal production.
REFERENCES
Alley, M.M., T.H. Pridgen, D.E. Brann, J.L. Hammons, and R.L. Mulford. 2009. Nitrogen
fertilization of winter barley: Principles and recommendations. Publ. 424-801. Virginia
Cooperative Extension, Blacksburg.
USEPA. 2012. Acid deposition [Online]. Available at:
http://cfpub.epa.gov/eroe/index.cfm?fuseaction=detail.viewInd&lv=list.listbyalpha&r=21
6610&subtop=341. Verified 15 Mar. 2012. United State Environmental Protection
Agency, Washington, D.C.
International Plant Nutrition Institute. 2003. Plant food uptake (PFU) for southern crops. Publ.
03-1364. International Plant Nutrition Institute, Norcross, GA.
USDA-National Agricultural Statistics Service. 2013. QuickStats [Online]. Available at:
http://www.nass.usda.gov/QuickStats/PullData_US.jsp. Verified 27 Mar. 2013. USDANASS, Washington, D.C.
3
TABLES AND FIGURES
Table 1. Average barley yield, test weight and moisture for sulfur source main effect; averaged
over sulfur rates, for barley grown on sandy loam soils in Essex County, Virginia.
Sulfur Source
Yield
Test Weight
Moisture
---bu/acre-----lbs/bu-----%--Sulfur + No Nitrogen
57.0 c
44.4 b
14.1 a
SulfN
69.2 b§
45.4 a
13.8 a
SulfN26
82.6 a
46.0 a
14.0 a
UAN+AT†
72.2 ab
46.1 a
13.9 a
N and S Control‡
44.7 d‡
43.8 b
14.1 a
S Control + N Fertilizer‡
61.4 bc
45.9 a
14.4 a
LSD0.10
11.1
0.7
0.6
†Urea ammonium nitrate + ammonium thiosulfate.
‡Control plots are not included in factorial analysis and are listed here for illustrational purposes
only.
§Within each column, means followed by different letters are significantly different at p=0.10
and were separated using Fisher’s protected least significant difference tests.
Table 2. Average barley yield, test weight and moisture for sulfur source main effect; averaged
over sulfur rates, for barley grown on sandy loam soils on the Eastern Shore of Virginia.
Sulfur Source
Yield
Test Weight
Moisture
---bu/acre-----lbs/bu-----%--Sulfur + No Nitrogen
25.9 c
43.2 bcd
11.2 a
SulfN
71.5 b§
42.6 d
11.1 a
SulfN26
76.4 a
43.7 ab
11.2 a
UAN+AT†
78.2 a
43.9 a
11.1 a
N and S Control‡
22.7 c‡
42.7 cd
11.2 b
S Control + N Fertilizer‡
74.3 ab
43.6 abc
11.2 a
LSD0.10
4.7
0.9
0.2
†Urea ammonium nitrate + ammonium thiosulfate.
‡Control plots are not included in factorial analysis and are listed here for illustrational purposes
only.
§Within each column, means followed by different letters are significantly different at p=0.10
and were separated using Fisher’s protected least significant difference tests.
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Table 3. Average barley yield, test weight and moisture for sulfur rate main effect; averaged over
sulfur sources, for barley grown on sandy loam soils in Essex County, Virginia.
Sulfur Rate
Yield
Test Weight
Moisture
---lbs/acre-----bu/acre-----lbs/bu-----%--10
73.1 a‡
45.7 a
14.4 a
20
70.3 ab
45.7 ab
13.9 a
30
67.3 ab
45.1 b
14.1 a
N and S Control†
44.7 c†
43.8 c
14.1 a
S Control + N Fertilizer†
61.4 b
45.9 a
14.9 a
LSD0.10
9.6
0.6
0.5
†Control plots are not included in factorial analysis and are listed here for illustrational purposes
only.
‡Within each column, means followed by different letters are significantly different at p=0.10
and were separated using Fisher’s protected least significant difference tests.
Table 4. Average barley yield, test weight and moisture for sulfur rate main effect; averaged over
sulfur sources, for barley grown on sandy loam soils on the Eastern Shore of Virginia.
Sulfur Rate
Yield
Test Weight
Moisture
---lbs/acre-----bu/acre-----lbs/bu-----%--10
62.0 b‡
43.0 ab
11.1 a
20
65.2 b
43.8 a
11.2 a
30
61.2 b
43.2 ab
11.1 a
N and S Control†
22.7 c†
42.7 b
11.2 a
S Control + N Fertilizer†
74.3 a
43.6 a
11.2 a
LSD0.10
4.1
0.8
0.2
†Control plots are not included in factorial analysis and are listed here for illustrational purposes
only.
‡Within each column, means followed by different letters are significantly different at p=0.10
and were separated using Fisher’s protected least significant difference tests.
5