Which Soils Should Respond To Sulfur Applications - Dr. Steve Culman, Ohio State University Extension, from the 2018 Conservation Tillage and Technology Conference, March 6 - 7, Ada, OH, USA. More presentations at https://www.youtube.com/channel/UCZBwPfKdlk4SB63zZy16kyA

1. WHICH SOILS SHOULD RESPOND
TO SULFUR APPLICATIONS
Conservation Tillage Conference
March 6, 2018
Steve Culman Sakthi Subburayalu
Ohio State University Central State University

2. Form Taken Major Concentration
Element up by plants Source in plants (avg)
Nitrogen (N) NO3
-, NH4
+ Organic matter, 1.5%
atmosphere
Phosphorus (P) H2PO4
-, HPO4
2- Soil minerals, 0.2%
organic matter
Potassium (K) K+ Soil minerals 1.0%
Calcium (Ca) Ca2+ Soil minerals 0.5%
Magnesium (Mg) Mg2+ Soil minerals 0.2%
Sulfur (S) SO4
2- Organic matter, 0.2%
precipitation
Sulfur abundance in plants
N > K > Ca > P = Mg = S

3. Why Sulfur? Why Now?
• Decreasing S deposited from atmosphere
• Increased crop yield = Increased S removal rates
• Reduced use of fertilizers containing S
• Fewer S - containing pesticides

4. Atmospheric Deposition of Sulfate - 2002 vs 2012

6. Atmospheric Sulfur Deposition
0
5
10
15
20
25
30
35
1990 1995 2000 2005 2010 2016
lbs/a
Year
NADP/NTN-OH 71 - Wooster
annual SO4 wet deposition 1990-2016

7. Sulfur Removal Rates in Grain
Corn
(lb/200 bu)
Soybean
(lb/70 bu)
Corn + Soybean
(lb/rotation)
8 12 20
• Corn grain: 0.04 lb/ bu
• Soybean grain: 0.18 lb/bu

8. Crop Removal of S
Crop Portion
Harvested
Yield/ acre S removed
(lb/acre)
Alfalfa Hay 5 tons 27
Corn Grain
Silage
200 bu
15 tons
8
25
Soybean Grain 70 bu 12
Oat Grain
Straw
80 bu
2 tons
5
9

9. Reduced use of fertilizers containing S
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
1960196419681972197619801984198819921996200020042008
PercentContribution
DAP MAP Other NP SSP
Most P fertilizers today contain little S

10. Reduced use of fertilizers containing S
• Manure
• 0.2-1.5% S
• ~ 50% of total manure sulfur is available in the first year of application
Livestock Type
Sulphur Content
Solid Manure
(lbs/ton)
Liquid Manure
(lbs/1000 gal)
total available total available
Dairy 1.5 0.8 3.5 1.9
Beef – all types 1.7 0.9 4.0 2.2
Swine – all types 2.7 1.5 7.6 3.5
Poultry 3.2 1.8 7.5 4.2

11. So then we need to fertilize with sulfur now?
How do we know when we need S?

12. S Plant Deficiencies
• Common in:
• Acid sandy soils
• Low SOM
• Cold, dry soils
• Delayed decomposition of OM
• Root restriction (S in subsoil)
“Most soils in Indiana, Michigan and Ohio will adequately supply needed
sulfur for plant growth. Sandy soils low in organic matter that are subject to
excessive leaching may not supply adequate sulfur. Crops such as wheat and
alfalfa that grow rapidly at cool temperatures when mineralization of S is slow
are most likely to be S deficient.”
Tri-State Recommendations,
1995

13. • Resemble N deficiency
• Pale greenish to yellow leaves
• Visible first on young leaves
• N symptoms on older leaves
• Often short term weather-induced
S Deficiency Symptoms

14. Testing for Sulfur Needs
• Soil tests - Not accurate for S needs
• Doesn’t measure organic S
• Sulfate S will change with rainfall
• No recommendations based on S Mehlich-3 extraction
• Tissue tests more accurate
• Strip trials with yield checks best tool

15. Tissue Sufficiency Ranges for S
Crop Growth Stage Range
Corn R1 – Silking; ear leaf 0.16 – 0.50%
Soybean Just before
flowering, upper
leaves
0.21 – 0.40%
Wheat Just before
flowering, flag leaf
0.21 – 0.40%

16. Sulfur Sources
• Elemental Sulfur
• Dry or in suspension
• Cheapest S source
• Ammonium Sulfate
• Additional N
• Gypsum (CaSO4)
• Potassium Sulfate & Potassium Magnesium Sulfate
• Additional K and/or Mg
• Ammonium Thiosulfate (NH4)2S2O3
• Source of elemental sulfur and sulfate
• Can be used in liquid or irrigation systems

17. Strip Trial Results

18. Soybean On-Farm Trials (2013-2014)
• 16 field trials in Ohio
• 9 in 2013; 7 in 2014
• Gypsum at 2 ton/acre at planting
• No influence of gypsum on soybean yield at any site
• R1 trifoliate leaves were within recommended range of 0.21- 0.4% S
• Bluck, Lindsey, Dorrance, Metzger. 2015. Agronomy Journal

19. Clark Wayne Wood
20152016
Check Gyspum Check Gyspum Check Gyspum
0
50
100
150
200
250
0
50
100
150
200
250
Treatment
CornYield(Bu/A)
Treatment
Check
Gyspum
OSU Farm - Corn Trials (2015-2016)
NS NS
NS
NS
NS
P= 0.06
Culman, unpublished data

20. Clark Wayne Wood
20152016
Check Gyspum Check Gyspum Check Gyspum
0
20
40
60
80
0
20
40
60
80
Treatment
SoybeanYield(Bu/A)
Treatment
Check
Gyspum
OSU Farm - Soybean Trials (2015-2016)
NS
NS
NS NS
NS
P= 0.07
Culman, unpublished data

21. On-Farm Corn Trials (2017)- Small Strip
Crawford Darke Fayette Licking Mahoning Van Wert Wyandot
Check S Check S Check S Check S Check S Check S Check S
0
100
200
300
Treatment
CornYield(Bu/A)
Treatment
Check
S
NS
NS NS NS NS
NS
NS
Minyo, Thomison Culman, unpublished data

22. On-Farm Corn Trials (2017) – Large Strip
Fulton.185 Fulton.186 Fulton.187 Fulton.188 Miami.205 Auglaize.206
Check S Check S Check S Check S Check S Check S
0
50
100
150
200
Treatment
CornYield(Bu/A)
Treatment
Check
S
NS NS
NS
NS
NS
P= 0.01
Richer, Bennett, Stachler, unpublished data

23. Organic On-Farm Trials (2017)
• 13 field trials on organic certified farms
• Wayne, Holmes, Franklin, Hardin and Logan Counties
• Mostly dairy farms, history of manure application
• 13 sites (7 corn, 5 alfalfa, 1 oat)
• Gypsum applied at 1 ton/acre
• No influence on alfalfa, silage corn, grain corn or oat yield at any site
• Significant differences in S levels in crops and soil with gypsum
• Fleuridor, Doohan, Culman, unpublished data

24. Additional Trials
• Ed Lentz
• Numerous years in corn and wheat
• Yield responses inconsistent and infrequent
• Dorrance and Lindsey in soybean (2017)
• 4 years of continuous corn with gypsum at 2 sites
• Compiling trials now to get picture of likelihood of crop
response to S fertilization

25. When S fertilization may benefit you
• Organic matter < 2%
• Coarse soil texture: sand, gravelly
• Poorly drained
• History of sulfur deficiency
S fertilization unlikely to benefit you
• Organic matter > 2%
• Medium soil texture: silt and clay
• Manure applied to the field
• Routinely apply foliar fertilizers
• No history of sulfur deficiency

26. Conclusions
• Corn and soybean trials showing yield responses to S are
still uncommon, although some responses have been
observed
• Soil testing for S needs has limited application – ‘good,
predictive’ soil test still to be developed
• Tissue testing recommended
• Might consider alternative tools for S management

27. Thank You
Steve Culman
Asst. Professor of Soil Fertility
Ohio State University
Wooster, Ohio
culman.2@osu.edu
330-822-3787
soilfertility.osu.edu