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

1. Is Crop Response to Sulfur
Application Likely?
Sakthi Subburayalua, Steve Culmanb , Eric Salasa, Warren Dick
a Agricultural Research and Development Program, Central State University, OH 45384
b School of Environment and Natural Resources, The Ohio State University, OH 43210
• Developed a model-based sulfur availability index
• The gSSURGO data, and other freely available geodatabases at
the national scale were processed to retrieve factors (layers) that
determine sulfur availability
• A sulfur availability index was computed for low and high sulfur
requirement crops
• A prototype GIS based web tool was developed for data retrieval
by end users

2. SULFUR AVAILABILITY MODEL
Based on 1473 soil
samples representing
443 soil series

5. N Index = S (mineralized) + S (deposited) –S (required by crops)
Crop
Requirement
Potential Total S
Input
( mineralized +
deposited) kg S
ha-1 year -1
Potential S
minus Crop S
requirement
(kg S ha-1 year -
1)
Net Availab-
-ility Index (N)
Low (High)
Low = 15 Kg
S/ha
High = 30 Kg
S/ha
0-10
(0-25)
-15 to -5
(-30 to -5)
0
>10-20
(>25-35)
-5 to 5
(-5 to 5)
2
>20-30
(>35-45)
5 to 15
(5 to 15)
3
>30-45
(>45-60)
15 to 30
( 15 to 30)
4
>45 (>60) >30 ( >30) 5

6. Variables Values Index
pH (P)
Source: gSSURGO
<4 1
4-6 2
>6 3
Percent Clay (C)
Source: gSSURGO
>28 1
14-28 2
<14 3
Precipitation (mm) (R)
Source: PRISM 30 yr Climate Normal
<700 1
700-850 2
850-1000 3
>1000 4
Hydrologic Soil Group (HSG)
Source: gSSURGO
D 1
B or C or Dual Group 2
A 3
Leaching Index (L)= Index(R+(C+P)/2+HSG)

8. S
Availability
Score
S Availability
Index
(SAI)
Response to S fertilization
will..
-10 to -7.5 Highly deficient Almost always occur
-7.5 to -6 Moderately
deficient
Usually occur
-6 to -3 Variably
deficient
Often occur depending on
specific crop conditions
(rainfall etc.)
-3 to -1 Sufficient Unlikely but might occur
under certain conditions
-1 to 1 Highly sufficient Unlikely under any
circumstances
Availability Score = N Index-L Index

9. Sulfur Availability for Low and High
Requirement Crops
Low-Requirement High-Requirement

10. How much of each State is cultivated?
Top 5 States with Largest Total Cultivated Area (in 1000 acres):
- Kansas
- Iowa
- North Dakota
- Texas
- Illinois

11. Percentage Distribution of the Five Sulfur Availability
Classes in Every State
(Low-Requirement Crops)
For Low-Requirement Crops
Example: 65.8% of the state of Iowa is
cultivated. The cultivated land is further
divided into these categories:
%
Highly Deficient 15.66
Moderately Deficient 33.41
Variably Deficient 50.50
Sufficient 0.42
Highly Sufficient 0.008

12. Percentage Distribution of the Five Sulfur Availability
Classes per State
(High-Requirement Crops)
For High-Requirement Crops
Example: 65.8% of the state of
Iowa is cultivated. The cultivated
land is further divided into these
categories:
%
Highly Deficient 21.85
Moderately Deficient 40.34
Variably Deficient 3.43
Sufficient 0.18
Highly Sufficient 0.00

13. States ranking in the "Highly Deficient” category
Low-Requirement Crops
About 98.3% of the
cultivated land in Georgia
falls under the “Highly
Deficient” category
State Code
%Relative to cultivated area
of each State
GA 98.3
SC 96.4
NJ 84.1
VA 83.0
NC 82.2

14. States ranking for the "Highly Deficient” category
High-Requirement Crops
About 99.5% of its
cultivated land falling
under the “Highly
Deficient” category
State Code
%Relative to cultivated area
in each State
GA 99.5
SC 97.9
DE 97.0
CT 94.5
MD 94.2

15. Sulfur Availability for Low and High Requirement
Crops in Ohio
Note: No county in Ohio has cultivated lands that belong to
the class “Highly Sufficient.”
Low-Requirement
Crops
High-Requirement Crops

16. Percentage Distribution of the Five Sulfur
Availability Categories per County
(Low-Requirement Crops)

17. Percentage Distribution of the Five Sulfur
Availability Categories per County
(High-Requirement Crops)

18. A prototype GIS tool for SAI data retrieval

19. ACKNOWLEDGEMENTS
This work is supported by Critical Agricultural Research and
Extension Program, grant no. 2016-68008-25036/CRIS no.
1009177 from the USDA National Institute of Food and
Agriculture.
THANK YOU