Canola Response to Sulfur (S) Fertilization
B. Schatz, E. Deiber, and B. Henson

The canola plant has a relatively high demand for sulfur (Franzen, 1997). Since fertilizer applications frequently lack this element, deficiencies in the field are not uncommon. This experiment was conducted on a low-S soil to evaluate the response of canola (Hyola 401) to 20 and 40 pounds S/acre in combination with 120 or 220 pounds total soil N/acre. Fertilizer formulations of S were also compared.

The application of 20 pounds S significantly increased test weight and yield, but no additional response was observed at the 40-pound rate (Table 1). Increasing the

N rate from 120 to 220 pounds/acre extended the bloom duration and days to physiological maturity, but did not influence yield or grain quality (Table 2). Neither S nor N significantly affected days to beginning bloom, height, or lodging (data not shown).

Applying S in a readily available form (ammonium sulfate) consistently improved yield compared to the control (Table 2). Commercial S fertilizers varied in effectiveness, with Kmag equal to ammonium sulfate, Tiger 90 less effective, and Sulfur 95 intermediate. Less soluble, elemental sulfur products (e.g. Tiger 90 and Sulfur 95) are useful for longer-term treatment. However, the response during the first season after application will likely be less than from formulations containing sulfur in a more readily available form for plant uptake.

The application of 20 pounds S/acre in a readily available form is recommended for canola fields where an S deficiency is anticipated.

Franzen, D. 1997. Fertilizing mustard and canola. NDSU Extension Service Bulletin SF-1122. North Dakota State University, Fargo. 4 p.

Table 1. Mean responses of canola to sulfur (S) and nitrogen (N) treatments, 1998.

 

S

 

N

Bloom Duration

Physiological Maturity

 

Test Weight

Kernal Weight

 

Yield

lbs/ac

lbs/ac

Days

DAP1

lbs/bu

g/200

lbs/ac

0

21.8

81.1

50.0

.62

2038

20

21.5

1.1

51.7

.65

2591

40

21.6

80.8

51.9

.64

2560

LSD (.05)

NS2

NS

1.0

NS

306

LSD (.01)

NS

NS

1.3

NS

424

1DAP = days after planting; 2NS = non-significant difference

 

Table 2. Growth and yield responses of canola to sulfur (S) and nitrogen (N), 1998.

 

S

 

N

Nutrient Source

Bloom Duration

Physiological Maturity

 

Ht.

Test Wt.

Kernal Wt.

 

Yield

lbs/ac

lbs/ac

Days

DAP1

cm

lbs/bu

g/200

lbs/ac

20

120

AS2 + Urea

21.0

80.2

103

51.5

.66

2498

40

120

AS + Urea

21.0

79.2

101

52.0

.63

2540

20

220

AS + Urea

22.0

82.0

104

51.9

.64

2685

40

220

AS + Urea

22.2

82.2

111

51.7

.64

2581

20

120

Tiger 90 + Urea

21.5

80.2

92

50.3

.62

2001

40

120

Tiger 90 + Urea

21.5

80.2

97

50.5

.62

2095

10+103

120

Tiger 90 + Urea + AS

21.2

79.2

101

51.8

.62

2361

20+203

120

Tiger 90 + Urea + AS

21.2

79.2

104

52.0

.63

2404

0

120

Urea

21.8

80.2

99

50.3

.63

2081

0

220

Urea

21.8

82.0

99

49.8

.62

1996

20

120

Sulfur 95 + Urea

21.2

79.8

96

50.8

.61

2210

40

120

Sulfur 95 + Urea

21.8

80.0

102

50.6

.63

2231

20

120

Kmag + Urea

21.0

79.0

107

52.0

.64

2497

40

120

Kmag + Urea

21.5

79.5

106

51.8

.65

2557

Mean

21.5

80.2

102

51.2

.63

2338

CV%

2.2

1.7

5.5

1.4

5.7

11.9

LSD (.05)

.7

1.9

8

1.0

NS

398

LSD (.01)

.9

2.4

11

1.4

NS

533

1DAP = days after planting; 2AS = ammonium sulfate; 3S applied as 50:50, Tiger 90:AS


NDSU Vice President,
Dean and Director for Agricultural Affairs
NDSU Extension Service ND Agricultural
Experiment Station
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