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Preliminary Results Soybean Survey 2015 (05/05/16)

Data collected from over 200 soybean fields in North Dakota were used for this report. A number of additional surveys are still being processed. In further analysis, interactions will also be examined.

Preliminary Results Soybean Survey 2015

Data collected from over 200 soybean fields in North Dakota were used for this report. A number of additional surveys are still being processed. In further analysis, interactions will also be examined.

Conclusions based on the 2015 grower survey data

  1. Planting soybean before mid-May, if conditions are favorable, may provide higher soybean yields.
  2. Seeding 155,000 to 165,000 seeds per acre provided the highest yields in 2015. NDSU is recommending to aim at 150,000 established plants per acre.
  3. Row spacing 15-22 inch provided the highest yields in 2015. The 30 inch row spacing had the lowest yield.
  4. Seed treatments resulted in higher yields in 2015.
  5. Fields with iron deficiency chlorosis (IDC) issues had 3.1 bushel lower yield than fields without IDC. It is critical to pick the right varieties (tolerant to chlorosis) for fields with IDC issues.

Planting before May 15 yielded 40.7 bushels per acre, mid-May (16-23 May) averaged 36.1 bushels per acre and later than May 23 planting yielded 31.5 bushels per acre (Table 1).

 

Table 1. Planting week in 2015 and yield in bushels per acre.

Planting timing 2015

Number of fields

Yield in bushels per acre

Last week in April

5

39.0

First week in May (1-7)

53

41.0

Second week in May (8-15)

15

40.2

Third week in May (16-23)

60

36.1

Fourth week in May (24-31)

54

33.0

First week in June (1-7)

20

27.3

Second week in June (8-15)

5

32.4

 

Table 2 gives the seeding rate averaged across the number of fields indicated in the second column. For seeding rates of approximately 165,000, it is estimated that the established plant density was around 150,000 plants per acre. This seeding rate provided the highest average yield in 2015.

 

Table 2. 2015 seeding rate and yield in bushels per acre.

Average Seeding rate 2015

Number of fields

Yield in bushels per acre

141184

20

35.0

150000

17

34.6

159200

31

36.4

165061

33

41.4

173596

52

36.5

182659

44

34.2

Average        166598

197

36.5

 

Table 3 provides the yield based on row spacing. Planting soybean with 30 inch row spacing resulted in the lowest average yield. This is similar to other NDSU research findings.

 

Table 3. 2015 row spacing and yield in bushels per acre.

Row spacing in inch 2015

Number of fields

Yield in bushels per acre

7.5

25

36.0

10

44

34.5

15

56

36.9

21

50

39.2

30

34

33.0

 

There is a yield benefit in rotating soybean with another crop (Table 4).

 

Table 4. 2015 yield of soybean after corn or soybean.

Previous crop

Yield in bushels per acre

Corn

39.4

Soybean

35.0

 

Seed treatments

80% of the growers used seed treatments and on average had a yield of 36.4 bushels per acre. 20% of the growers did not use seed treatments and on average had a yield of 35.0 bushels per acre.

Iron deficiency chlorosis

69% of the growers indicated that they did not have iron deficiency symptoms in their field and on average had a yield of 37.5 bushels per acre. 31 % of the growers indicated that they had some iron deficiency chlorosis in their fields and on average these fields yielded 34.4 bushels per acre.

We want to thank all soybean growers who participated in the 2015 soybean survey for their contributions and all extension staff assisting in gathering the information.

 

J Stanley

NDSU Soybean Survey Coordinator

&

Hans Kandel

Extension Agronomist Broadleaf Crops


 

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