Sulfur: The Good, the Bad,
and the Yellow
Lesley Lubenow
Area Extension Specialist
Langdon REC
WHY WAS 2014 SO BAD
& WHAT ABOUT NEXT YEAR?
General Look of S Deficiency
Small Grains: New growth is pale, yellow
Corn: New growth is striped yellow
Canola: Purpling or Reddish Leaf Margins
Cupping
All: Less Vigor/Shorter, Delayed Maturity
Insert Photo of S
defiency
Photo From: SDSU Extension, Common Nutrient Deficiency Symptoms in Corn
Kings of Sulfur Prediction
Soil Type: Low soil organic matter, coarse
textured soils, eroded soil areas
The Environment:
Cold spring weather
Continuous wet
Leaching situations ie. snow banks melting
by tree rows
When did we start to see S
problems?
Answer:
Source: John Lukach, personal correspondence
1993
2014
Observed S deficiency in traditional canola
growing areas
Observed S deficiency in new places…..
Wheat & Corn fields in Traill, Nelson, Steele
Like a kid in the candy store!
North Dakota June 2014 Precipitation Percent of Normal
(1981-2010)
Grafton NDAWN station received at least a half inch of rain every 3 to 6
days from May 19 to June 23
Other Considerations
Heavy Crop Consumption
Yearly Atmospheric Deposition –
3-4 lbs/acre of S as SO4
Quirky S Things
High N can increase severity of sulfur
deficiencies
Sulfur can vary widely in the field
High Clay Soils can have S deficiency
Very unusual, but occurred in 2011 &
2014.
Grower used 10 lb S
as Ammonium thio
in 2 X 2 band
Greenest are checks
Yellowest areas are high N plots
Photo from Dave Franzen, NDSU
IS THE SULFUR SOIL TEST
RELIABLE...
Soil test sulfur values are not reliable to use
for a numeric addition of sulfur.
Soils tests between “Good” and “Bad” yellow
sites are useful for diagnosis of S issues.
Tissue tests are useful. A test result with a
more than 16-20 parts N:1 part S may
suggest insufficient plant S.
HOW DO WE REMEDY SULFUR
PROBLEMS…
The Backstory
Re: Sulfur is variable in fields
Yield potential may be much less in low S
areas.
The outcome of sulfur addition is not 1+1= 2,
but is part of a dynamic system of OM, soil
physical and chemical properties, and biology
Elemental Sulfur
Avoid use.
Conversion of elemental sulfur to plant
available sulfate is too slow.
The leachable nature of sulfate does not
allow for “saving” S for times of plant need.
Yellow Mirroring Nutrient Deficiency
Wet conditions can leach S & N just outside
the root zone.
Also, general yellowing can be observed
when soil temps are cool and spring temp’s
radically jump to 80°F on very small rooted
corn.
Flickr user: tinyfroglet
Canola S Rescue
General advice:
20 lbs of S, but 10 lbs of S is probably
sufficient.
If yield potential is 3000 lbs/a canola, then
use 20 lbs of S/a.
Canola S Rescue
Timing: Earliest is best. Recovery yields may decrease as
plant grows.
Treatment at Bolting
Yield (lb/a)
Control – 0 lb S/a
290
10 lb S/a
613
20 lb S/a
870
Comparison to Good S+ Adjacent Area
919
Lukach, Rock Lake ND, 1995
Last possible timing: Early Flowering, but green seed
issues/shatter from maturity delay can occur
Wheat S Response
Plants need between 20-30 lbs of S.
If very wet/snowy winter/spring, a pre-emptive
spring application can be considered.
Amount needed: 10 lb. S/acre. Apply no
later than 5 to 7 leaf stage.
In most cases, sulfur application is cost-effective on coarse/low OM areas.
Corn S Response
Pre-emptive application can be considered.
No Ammonium Thiosulfate with Seed
Rescue Timing: Early is best.
Amount Needed: 10 lb. S/acre
Liquid fertilizer placed between rows, Dry fertilizer
up to V4.
SHOULD I FERTILIZE IN THE FALL
OR SPRING FOR SULFUR…..
The Sulfate Ion is…….
Leachable
Controlled by water amount and ease of
water movement through soil column
If no fertilizer applied in fall, then no chance of
leaching.
Sulfur is a spring fertilizer (Sorry)
Conclusions
Sulfur is a complex plant nutrient.
Rescue treatments are doable.
Avoid Elemental Sulfur.
Producers should be mindful of soil & weather
risks which produce low S conditions.