Classification of soybean by maturity groups is based on the duration of the period from emergence to full maturity, which ranges from 80 to more than 140 days. In addition to calendar days, a system of cumulative active temperatures or Crop Heat Units is used to evaluate varieties, which allows for more accurate ripening predictions considering the specifics of the crop as a short-day plant.
Varieties are categorized as ultra-early (80–100 days), mid-season (105–120 days), and late-maturing (120–140+ days). Late-maturing forms possess higher yield potential and often increased protein content, yet they require a long warm period. Early-maturing varieties are prioritized for northern zones and arid regions, allowing them to avoid the risk of incomplete ripening due to autumn frosts.
The use of varieties from different maturity groups in crop rotation is a key agronomic technique for stabilizing production. It helps to mitigate the negative impact of specific yearly weather anomalies and optimizes the timing of field operations, including clearing fields for winter crop sowing.
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Maturity group.