A look at the sulphur, calcium, and magnesium requirements for crop production in Ontario. John Lauzon, University of Guelph

1. Sulphur, Calcium and
Magnesium in Ontario
John Lauzon

2. Sulfur Cycle
Sulfides Sulfate
Organic Matter
fertilizer
reduction
volatilization
H2S
SO2
Burning fossil fuel
H2S, SO2
Soil Minerals
leaching
harvest
Plant
uptake
oxidation
SO4
Erosion
runoff
Elemental S
oxidation

3. Need For Sulphur in Ontario
• 1880's gypsum (land plaster)was commonly applied
in Ont. (applied as early as the mid 1700’s)
• Recent work is starting to show sulphur response
• After 1950 ammonium phosphate became common
(very little S)
• About 1880 super phosphate (0-20-0) was introduced
(14 % S)

4. Sulphate (SO4) wet Deposition
1990 - 2015
Environment Canada

5. Estimates of Anthropogenic Sulphur Dioxide
Emissions: 1850–2005
0
5000
10000
15000
20000
25000
30000
35000
40000
1840 1860 1880 1900 1920 1940 1960 1980 2000 2020
Emission(Ggyr-1)
North America
Western Europe
China
Smith et al 20111 Gg = 1 000 000 kg

6. Sulfur Crop Uptake and Removal
Canadian fertilizer institute, 1998
Crop yield S uptake S removal
(kg ha-1)
Grain corn 9500 15 - 18 11 - 12
Soybean 3400 19 6
Winter wheat 5100 17 - 21 7
Mixed Hay 1st 11200 17 - 34
Mixed Hay 2nd 6700 11 - 17
Cabbage 78 000 73 - 90
Potato 44 800 20
Canola 2 600 1730- 34

7. Sulphur Responsive Crops in Ontario
• Alfalfa
• Canola
• Winter wheat
• Corn ?
• Soybean ?
Cowen

8. Alfalfa Response to Sulphur in 1977
based on average of 2 N rates
Sulphur application rate (kg S/ha)
Cut 0 30 60 90
Forage yield (kg/ka)
1 4680 4940 5100 4500
2 3200 3110 3040 3040
3 2430 2220 2170 2300
total 10300 10300 10300 9900
(Sheard 1977)

9. Alfalfa Sulphur Response in 2012
North of Fergus (Harrop)
First Cut Yield
kg/ha
4566 b
4474 b
6821 a
Treatment
Control
225 kg KCl/ha
270kg K2SO4/ha
First Cut Alfalfa
% of stand
31 b
35 b
56 a
Third Cut Yield
kg/ha
968 b
1067 b
2180 a
Lauzon and Ball 2012
52 % 104 %
All of the increase was due to greater alfalfa growth
Dry year

10. Alfalfa Sulphur Yield Response in 2013
Treatment Wallenstein
(Logel)
Hesson
(Runsteder)
Listowel
(McLagan)
First Second First Second First Second
Yield (kg/ha)
Check 6817 2556 5078 2639 a 2833 2189 a
Fall 50 kg/ha elemental S 6583 2767 4575 3401 ab 3094 2531 b
Fall 100 kg/ha elemental S 6732 2830 5247 3715 b 3128 2482 b
Potassium Sulphate 55 kg
S/ha
6897 2768 4712 3352 ab 3138 2468 b
Potassium Chloride Same
K level
6718 2507 4627 2703 a 2824 2163 a
Bonnie Ball
Wetter than normal until Aug.

11. Alfalfa Sulphur Uptake Response in
2013
Treatment Wallenstein
(Logel)
Hesson
(Runsteder)
Listowel
(McLagan)
First Second First Second First Second
(kg/ha)
Check 6.6 a 3.2 a 4.3 3.2 a 5.0 a 3.3 a
Fall 50 kg/ha elemental S 8.0 a 4.1 a 5.8 5.7 b 7.8 b 6.5 b
Fall 100 kg/ha elemental S 8.0 a 5.3 b 4.4 8.0 c 9.8 b 8.5 b
Potassium Sulphate 55 kg
S/ha
12.0 b 5.7 b 5.3 8.5 c 9.9 b 6.7 b
Potassium Chloride Same
K level
6.7 a 3.5 a 3.6 3.2 a 5.0 a 3.2 a
Bonnie Ball

12. Alfalfa Sulphur Yield Response in 2014
near Lynden Sand texture
0
2000
4000
6000
8000
0 10 20 30 40
S kg/ha
Yield(kg/ha)
1st cut
0
1000
2000
3000
4000
0 10 20 30 40
S kg/ha
Yield(kg/ha)
2nd cut
Close to normal precipitation

13. Alfalfa Sulphur Yield Response in 2014
Elora Research Station Silt loam texture
0
2000
4000
6000
8000
0 20 40 60
1st Cut
S kg/ha
Yield(kg/ha)
0
1000
2000
3000
4000
0 20 40 60
2nd cut
S kg/ha
Yield(kg/ha)
0
500
1000
1500
2000
2500
0 20 40 60
3rd cut
S kg/ha
Yield(kg/ha)
Close to normal precipitation

14. Sulphur on Alfalfa
• Of the 11 trials, 6 of the sites responded
• Soil texture and organic matter did not dictate response
• Potentially dry years responded more (not always)
• Older stands tended to respond more

15. 2010 Canola Sulphur Trials
Site No Sulphur 24 lbs/ac sulphur
Yield kg/ha
Owen Sound 3884 a 4072 b
Arthur 807 a 1391b
Fergus 1695 a 2117 b
Port Elgin 3517 a 3710 b
Brian HallWetter than normal until Aug

16. 2014 Canola Sulphur Responses
Close to normal precip
0
500
1000
1500
2000
2500
3000
3500
0 10 20 30 40 50
Yield(kgseed/haas
DM)
Listowel
0
500
1000
1500
2000
2500
3000
3500
0 10 20 30 40 50
Camilla
0
500
1000
1500
2000
2500
3000
3500
4000
0 10 20 30 40 50
Yield(kgseed/haas
DM)
Owen Sound
y= 3002 +34.7x -0.64x2
R2 =0.64
0
1000
2000
3000
4000
0 10 20 30 40 50
Yield(kgseed/haas
DM)
S application rate (kg S/ha)
Elora
0
500
1000
1500
2000
2500
3000
0 10 20 30 40 50
S application rate(kg S/ha)
Kimberley
y= 2294+14.6x-0.24x2
R2 = 0.60
(Haupt 2017)Brian Hall

17. Canola sites
• 28 sites in total between 2010 - 2015 with a positive response at 13 sites
• No clear way of predicting responsive sites

18. 2005 and 2006 Johnson Wheat Trials
No Sulphur Sulphur
Yield (bu/ac)
Carthage 05 83.2 89.3
Stratford 05 89.3 93.5
Lucan 99.2 95.5
Lucan 2 95.2 93.8
Perth 72.6 68.5
Carthage (2006) 69.9 69.2
Nairn 103.1 106.0
Brantford 57.6 57.6
Average 83.8 84.2

19. Sulphur Response on Winter Wheat
2011 - 2014
S Rate (lbs
S/ac)
Yield (bushels/acre)
2011 2012 2013 2014 Avg.
Number of
sites
5 11 10 14 40
0 95.2 101.4 80.2 91.6 91.0
5 - -0.5 +0 +4.6 +1.4
10 - +1.2 +1 +4.7 +2.3
20 4.5 +0.6 +1.3 +4.3 +2.6
40 +0.8 - +4.1 -
Follings, Field crop news 2017.
(Peter Johnson)
12 of the 40 sites responded

20. 2018 Wheat Sulphur Trials
Check With Sulphur
Yield (kg ha-1)
Elora 8050 8180
Sombra 5860 5590
Stayner 7090 7160
Average 7000 6975

21. Sulphur On Winter wheat
• Ontario research to date suggests optimal rate of 10 kg S ha-1
• Less than 1/3 of sites responded
• We need to dig into the data more, but No Clear way of predicting
responding sites

22. 2006 Corn Sulphur Trial Sites by Middlesex
S.C.I.A.
Site Soil S (ppm) Corn yield
With S
Corn Yield
No S
bu ac-1
SJL 39.8 174 172
SMR 18.7 162 166
SSF 23 159 157
SNS 13.9 177 176
SRB 19.8 161 163
SKP 20.6 165 168
STL 17.7 194 196
SMA 18.5 154 143
SRM 46.9 130 134
SJF2 20.6 172 174
SJF3 20.6 182 182
SBP 25.9 170 169
SFH 30 167 185
Average 24 167 168
http://www.gocorn.net/v2006/Rotation/articles/Peas%20and%20Sulphur.html
Peter Johnson

23. 2012- 2018 Corn Sulphur trials
2012 2013
Number of sites 5 6
Yield (kg/ha)
No Sulphur 9927 10956
With Sulphur 9736 10818
Stewart 2012 and 2013, Lauzon and Sanders 2016 and 2018
No Significant responses at any sites
2016 (Elora)
1
12190
11420
2018 (Elora)
1
14740
14410

24. 20 lbs of S 0 lbs of S
Dale Cowan

25. Sulphur of Corn in Ontario
• Industry has indicated observing responding sites
• Sulphur widely applied to corn in Ontario
• No response seen on any sites evaluated

26. Soybean Sulphur Response
2018
Check With Sulphur
Yield (bu/ac)
Bornholm 1 72.5 74
Bornholm 2 69.6 77.9
Winchester 56.9 55.9
Elora 45.5 46.3
Average 61.1 63.5
Bohner
Ammonium sulphate applied the check was not corrected for the nitrogen
content in the first 4 sites
Arkona 58.4 60
Merlin 55.8 57
Elora 64 65
Average 59.4 60.7
Sanders and Lauzon

27. Summary
• Sulphur deposition has drastically decreased in Ontario
and may be continuing to decrease
• We have seen response on about ½ of the alfalfa and
canola sites, 1/3 of the winter wheat sites tested.
“Rarer” response on corn and soybean
• Greater probability of response would be expected on
sandy and/or low organic matter soils; however, this
was not seen in the trials
• More sites needed to determine if we can predict the
response to sulphur

28. Calcium and Magnesium Cycles
Soil Organic matter
Ca2+, Mg2+
Exchangeable
Microbial/ Plant
uptake
Harvest export
Erosion
Fertilizer/Lime
Clay
solution
leaching
Mineral Ca/Mg

29. Ca Crop Uptake and Removal
Crop yield Ca uptake Ca removal
(kg ha-1)
Grain corn 9500 28 - 56 1
Soybean 3400 28 - 34 10 - 12
Winter wheat 5100 15 2
Mixed Hay 1st 11200 90 - 157
Mixed Hay
2nd
6700 78 - 112
Cabbage 78 000 95
Potato 44 800 22 6

30. Possible Ca Deficiencies
• Blossom end rot in tomatoes (can also indicate moisture stress)
physiological disorder
• Black-heart in celery
• Bitter pit in apples
• Pod growth in peanuts
• Club root in cauliflower
• Tip dieback in cabbage

31. Soil Calcium Deficiencies in Southern
Ontario
• Dry soil or root pruning
Typically these soils will be limed, most liming material
contain calcium
Adding calcium is unlikely to help this situation, but
irrigation will
• Ontario agricultural soils formed from high calcium rock,
as such calcium is typically extremely high
• Acid, sandy , highly leached soils with low CEC

33. Magnesium Crop Uptake and Removal
Crop yield Mg uptake Mg removal
(kg ha-1)
Grain corn 9500 20 - 34 15
Soybean 3400 23 - 34 8 - 10
Winter wheat 5100 19 - 26 14
Mixed Hay 1st 11200 20 - 34
Mixed Hay
2nd
6700 17 - 28
Cabbage 78 000 40
Potato 44 800 45 11

34. Soil Magnesium Deficiencies
• Acid, sandy , highly leached soils with low CEC
• Calcareous soils with low Mg levels
• Acid soils with low magnesium limed with calcitic limestone
• Crops with high requirement or need for low soil pH

36. Interpreting Soil Mg Test Results
Official
If soil test Mg is below 20 ppm Mg should be applied at 30
kg /ha for field crops.
Unofficial
Agronomy Guide for Field Crops
If soil test Mg is below 100 ppm and the soil pH is low, use
dolomitic limestone to correct the pH. Dolomite contains
high amounts of magnesium

37. Summary
• Calcium Magnesium and Sulphur are all require plant
elements
• Calcium unlikely to be limiting in agricultural soils of
Ontario
• Soil test will indicate if magnesium is low.
• More work is needed on sulphur to determine under
what conditions it is needed, but I would apply on crops
that have a high possibility of responding.

38. 2019 Field Trials
We are currently looking for grower cooperator trials for
sulphur research. If you are interested please contact:
Joanna Follings
OMAFRA
EMAIL: joanna.follings@ontario.ca
Phone: (519) 271-8180