Should you plant earlier maturing soybean varieties?

Selecting earlier maturing soybean varieties can reduce the potential for harvest delays.

Snow cover on late-maturing soybeans in 2014.
Snow cover on late-maturing soybeans in 2014.

On average, only 73 percent of the Michigan soybean crop was harvested before the end of October between 2012 and 2016. These significant harvest delays create several problems for soybean producers such as preventing wheat planting and fall tillage operations, increasing harvest losses, early snow cover (see photo) and increasing soil compaction and harvest ruts due to harvesting when the soil is too wet. The weather conditions occurring at planting, during the growing season and at harvest are by far the leading contributors to soybean harvest delays. Producers cannot control the weather. However, they can make some important management decisions that will reduce the potential for significant harvest delays.

There are three ways producers can reduce the potential for soybean harvest delays:

  1. Increase planting capacity.
  2. Increase harvesting capacity.
  3. Select earlier maturing varieties.

The first two options involve increased equipment and labor costs. This article will focus on the last option, selecting earlier maturing varieties as no additional costs are associated with this option.

A recent analysis of the relationship between soybean maturity group and yield in Michigan revealed that soybean maturity group and yield are not closely correlated as long as producers select the highest-yielding varieties within the adapted maturity range for their location. The analysis also showed the range of maturity groups adapted to the central zone was 1.8 to 2.6, and between 2.4 and 3.2 in the southern zone over the eight-year period (2009-2016). The average yields and maturity dates for the top-yielding varieties from each maturity group entered in the Michigan Soybean Performance Report are listed in Tables 1 and 2. The maturity dates represent the dates when 95 percent of the pods attained their final color and cracked open under finger pressure. Depending on the weather, this is at least five days before harvest operations can begin.  

Table 1. Average soybean yields and maturity dates for the top four varieties in each maturity group from the central zone of the Michigan Soybean Performance Reports (2009-2013).

 

Soybean maturity group

1.8

1.9

2.0

2.1

2.2

2.3

2.4

2.5

2.6

Average yield (bu/ac)

65.8

66.0

66.6

67.0

66.3

64.3

66.6

66.2

65.7

*Average maturity date

9/19

9/19

9/20

9/21

9/22

9/23

9/25

9/24

9/26

Average planting date

May 23

*Average maturity dates are from 2009 to 2012. Maturity dates were not available after 2012.

Table 2. Average soybean yields and maturity dates for the top five varieties in each maturity group from the southern zone of the Michigan Soybean Performance Reports (2009-2013).

 

Soybean maturity group

2.4

2.5

2.6

2.7

2.8

2.9

3.0

3.1

3.2

Average yield (bu/ac)

71.5

70.2 69.7 70.2 70.5 69.8 70.2 70.2 70.1

*Average maturity date

9/25

9/25

9/27

9/28

9/29

9/30

10/1

10/2

10/3

Average planting date

May 24

*Average maturity dates are from 2009 to 2012. Maturity dates were not available after 2012.

The information in Tables 1 and 2 clearly shows yield is not affected by maturity group provided the highest-yielding varieties within the adapted range of maturity groups for the area are selected. The tables also show a high correlation between maturity group and maturity date and subsequent harvest date. On average, harvest operations are delayed by one day for each 0.1 increase in soybean maturity group. For example, a producer in the Saginaw Valley planting varieties from the 2.0 maturity group instead of the 2.5 maturity group should be able to harvest five days earlier. Assuming a harvest capacity of 80 acres per day and five days of good weather, the producer could knock out 400 acres before the group 2.5 varieties were ready to harvest.

The benefit of planting earlier maturing varieties will vary from farm to farm. In general, the biggest gains will be realized by farms that: 

  • Have fields with poorly drained, fine-textured soils.
  • Plant a high percentage of their acreage to full- season varieties.
  • Plant varieties from maturity groups exceeding the upper end of the range of adapted maturity groups for their area.
  • Have limited planting and harvest capacity.
  • Don’t have the option to dry soybeans.

Producers should always plant a range of maturity groups and select the highest yielding varieties available within the adapted maturity group range. However, producers that frequently harvest soybeans in November should plant a higher percentage of varieties from the earlier end of the adapted range.

This article was produced by the SMaRT project (Soybean Management and Research Technology). The SMaRT project was developed to help Michigan producers increase soybean yields and farm profitability. The SMaRT project is a partnership between Michigan State University Extension and the Michigan Soybean Checkoff program.

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