Influence of environment and management practices on soybean seed composition in North Carolina

Abstract

Soybeans [ Glycine max (L.) Merrill] are a valuable source of protein and oil used for industrial, agricultural, and culinary purposes. It is important to understand how shifts in management practices influence not only soybean yield but also soybean quality parameters, like protein and oil content. Between 2019 and 2023, field trials were installed at 19 different environments across North Carolina for a total of 2775 plots used in this analysis. Trials were set up to access the impact of management factors, such as soybean planting date and maturity group (MG), on soybean yield, soybean protein and oil content, and soybean damage and purple seed stain. Soybean protein and oil content were inversely related across NC regions, MGs, and planting dates. The relationship between soybean yield and protein was minimal. Soybean protein content was typically higher for later maturing varieties (>MG4), while the inverse was observed for oil content, which was lower with later maturing varieties. Across all environments, as average reproductive temperatures increased, yield, protein, and oil generally increased as well. There was a minimal relationship between soybean yield and soybean seed damage and purple seed stain. Growers can use this information to make more informed management decisions regarding the impact of planting date and MG selection on soybean seed composition and quality.