Selecting earlier maturing soybean varieties can reduce the potential for harvest delays.
Snow cover on late-maturing soybeans in 2014.
For the past two years, 15 percent of the Michigan soybean crop was still in the field as of Nov. 9. The 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 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:
- Increase planting capacity.
- Increase harvest capacity.
- 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 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 five-year period (2009-2013). 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)
|
61.9
|
62.1
|
62.3
|
62.5
|
62.7
|
60.1
|
63.3
|
62.3
|
62.2
|
|
*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 21
|
*Maturity dates for 2013 were not available.
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)
|
68.5
|
66.8
|
66.0
|
66.0
|
67.1
|
66.2
|
66.7
|
67.5
|
66.5
|
|
*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 25
|
*Maturity dates for 2013 were not available.
The information in Tables 1 and 2 clearly shows yield is not affected by maturity group as long as the highest-yielding varieties are selected within the adapted range of maturity groups for the area. 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 2.1 group beans instead of 2.6 beans will 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 2.6 beans 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:
- 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 still plant a range of maturity groups and select the highest yielding varieties available within the adapted maturity group 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.