Brazil is the world's largest producer and exporter of soybeans ( Glycine max L. Merr.). Assessing yield gaps (Yg) is essential for improving resource use efficiency and guiding farmers’ management strategies. The objective of this study was to estimate soybean yield potential (Yp), water‐limited yields (Yw), and Yg based on water and agricultural practices across Brazil's five soybean macroregions. We have quantified yield losses due to delayed sowing and evaluated interannual yield variability caused by environmental and climatic factors. The results revealed that the southern regions had the highest Yp values but also the largest Yg values, which were strongly influenced by climatic factors. In contrast, the Brazilian Midwest had the lowest Yp yet minimal water‐related Yg, with relatively stable yields over time; here, Yg were primarily due to crop management rather than climatic constraints. In northern macroregions, lower Yp was observed with moderate climatic influences. Delayed sowing reduced Yp across all macroregions, with the greatest losses occurring in regions with initially high Yp, particularly in the south. Each macroregion has unique environmental conditions that lead to different patterns of Yp, Ya (actual yield), and Yw. In the southern macroregions, Yg are primarily due to water constraints, indicating potential benefits of irrigation, while the Midwest, which has the lowest Yg, improved crop management practices offer the most significant opportunity for yield gains.

The aim of this study was to identify plastochron phases in soybean cultivars with determinate and indeterminate growth habits. Experiments were conducted from 2010/2011 to 2022/2023 at four locations in Rio Grande do Sul state (RS), Brazil, using 25 soybean cultivars with determinate (6) and indeterminate (19) growth habits. This study divided the plastochron into phases during the soybean node emission stage. In irrigated cultivars with a determinate growth habit, the plastochron has an early and late phase of 59.7 and 65.7 °C day node^-1, respectively. In rainfed (non-irrigated) environments, there is no difference between the early and late plastochron phases. The early and late plastochrons of irrigated cultivars with an indeterminate growth habit are 64.1 °C day node^-1, while the intermediate phase is 58.5 °C day node^-1. In rainfed environments, the average value of the early and intermediate phases is 60.6 °C day node^-1, with a late plastochron of 79.4 °C day node^-1. Dividing the plastochron into phases during node emission, as proposed in this study, improves understanding of vegetative development in soybean cultivars with determinate and indeterminate growth habits and establishes ecophysiological foundations for chronological function construction.