Assessing Variation in US Soybean Seed Composition (Protein and Oil)

Area of Science:

• Agricultural Science
• Agronomy
• Plant Science

Background:

• Soybean seed composition and yield are influenced by genetics, environment, and management.
• The specific contributions of these factors are not fully understood.
• A comprehensive synthesis-analysis is needed to elucidate these interactions.

Purpose of the Study:

• To identify the main effects of genetics (G), environment (E), and management (M) on soybean seed composition (protein and oil) and yield.
• To quantify the influence of various management practices on soybean productivity.
• To understand the G × E × M interactions in soybean production.

Main Methods:

• Synthesis-analysis of a large dataset (13,574 data points) from 21 US studies (2002-2017).
• Analysis of environmental factors (site-year) and crop management practices.
• Statistical evaluation of the impact of delayed planting, crop rotation, fertilizer N, and maturity groups on yield and composition.

Main Results:

• Environment (site-year) was the dominant factor, explaining >70% of variation in seed composition and yield.
• Delayed planting reduced oil concentration and yield, particularly at northern latitudes.
• Corn-soybean rotation positively impacted yield and composition compared to continuous soybean.
• Nitrogen fertilizer influenced oil, protein, and yield differently based on application rates.
• Southern latitudes showed reduced oil and increased protein with later maturity groups.

Conclusions:

• Environment is the primary driver of soybean yield and composition variability.
• Specific management practices, such as planting dates and crop rotation, can be optimized for improved outcomes.
• Further research into G × E × M interactions is crucial for advancing soybean production strategies.