Planting Date, Maturity, and Temperature Effects on Soybean Seed Yield and Composition

Abstract

Core Ideas Planting date and maturity group decisions can greatly affect yield and composition. Temperature had a significant effect on seed yield and composition. Planting date × maturity group should be chosen based on the product's end use. Soybean [Glycine max (L.) Merr.] production has greatly increased in the upper U.S. Midwest over the last decade, but little information exists regarding the interactive effects of environment and spring management decisions on soybean seed yield and composition. Our objective was to assess the effect of four planting dates (PDs), four cultivar maturity groups (MGs), and ambient temperature between R5 to R8 (T5–T8) on soybean seed yield and composition. Field studies were established between 2014 and 2016 at three locations in Wisconsin and one in Minnesota. Across environmental conditions and management decisions, greater seed yield was positively correlated with protein and oil contents but negatively correlated with linoleic, linolenic, and sucrose contents. Multivariate data analysis showed positive synergies between early planting (late April–early May) and MG 2 for yield, oil, and oleic acid across the examined region. A MG 2 was the highest yielding and a ∼1200 kg ha−1 yield difference was observed between early and late PDs. These results underline the complexity of the soybean yield‐composition relationships. Additionally, the large variability in the responses of constituents to management decisions and temperature variations highlights the importance of a producer knowing the product's end use (e.g., high yield vs. high protein) and accordingly modifying the growing environment by selecting an appropriate PD and MG for the respective region. To provide more accurate recommendations to a broader range of producers, multi‐environment studies are imperative to capture large environmental variability in important soybean production areas across the United States.

Effect of seeding date, environment and cultivar on soybean seed yield, yield components, and seed quality in the Northern Great Plains

“…Inconsistent effects of seeding date on protein concentration have been reported from Quebec (Tremblay et al., 2006). Cultivar had little effect on seed protein concentration, accounting for <1% of the total variance, and is consistent with a study in Wisconsin that explored the same in soybean maturity groups from 0.6 to 2.0 (Mourtzinis et al., 2017). The lowest protein concentration occurred at Portage17, which received the lowest rainfall throughout the growing season and specifically in August which corresponded with the seed‐fill period.…”

“…(2006) in Quebec and partially agree with Mourtzinis et al. (2017) who found seed oil concentration to be mainly affected by seeding date (lower oil with late seeding) and to a lesser degree by maturity grouping. Temperature during seed filling has been related to regional soybean seed oil concentrations in Minnesota such that oil increases at a rate of 6.6 g kg −1 °C −1 (Naeve & Huerd, 2008).…”

“…In Wisconsin, Mourtzinis et al. (2017) consistently observed higher protein and lower oil with late seeding because of lower temperatures between the R5 and the R8 soybean development stages, concluding that management decisions to maximize seed yield and seed composition may be difficult to attain. Inconsistent effects of seeding date on protein concentration have been reported from Quebec (Tremblay et al., 2006).…”

“…Although widely reported, a consensus has not been reached on the interactions between weather, developmental stage, and soybean seed quality components. Generally, increased temperatures during late reproductive stages have been linked to increased oil concentration (Mourtzinis, Gaspar, Naeve, & Conley, 2017; Naeve & Huerd, 2008; Song et al., 2016) and in some instances, reduced protein (Mourtzinis et al., 2017; Song et al., 2016). The effects of growing season moisture conditions on seed quality are less clear.…”

Amino Acid Balance is Affected by Protein Concentration in Soybean

“…Using protein as a gauge of soybean value assumes that the relative abundance of amino acids is static. However, numerous reports on both whole soybean and soybean meal have shown that the relative abundance of some or all of the five limiting amino acids within the protein is negatively correlated with protein (Thakur and Hurburgh, 2007;Medic et al, 2014;Warrington et al, 2015;Miller-Garvin and Naeve, 2016;Mourtzinis et al, 2017). A characterization of a decade of US soybean sample analysis showed that the amino acid balance of all five limiting amino acids decreased with increased protein concentration, and the balance was made up by increased relative abundance of glutamic acid and arginine within the protein (Medic et al, 2014).…”