Genetic progress is assessed to estimate its contribution to on‐farm yield increases and to identify traits that have been improved over some period of time. Although Argentina is a major soybean [Glycine max (L.) Merr.] producer, there is limited information about genetic progress in this system. Argentinean soybean cultivars were developed from US commercial cultivars. Because the genetic base of US cultivars is narrow, it would be expected that genetic progress in Argentina to be slower than in the United States. We assessed the genetic gain for yield and related traits in cultivars released in Argentina from 1980 to 2015. One hundred and eighty‐one cultivars belonging to maturity groups (MGs) III, IV, and V were evaluated in three environments in the northern pampas from Argentina. Genetic gain in yield was 43 kg ha−1 yr−1 and was not different across MGs. Relative genetic gain was 1.1% yr−1, similar to reports from the United States or Brazil. Newer cultivars from MGs III and IV had increased days to maturity, while cultivars from MG V showed the opposite trend. Vegetative period was also reduced in newer cultivars from MGs IV and V. Seed protein concentration was reduced over the years. Genetic progress explained 50% of total on‐farm yield increase. Results from this experiment showed that breeding programs in Argentina were able to attain a similar genetic gain to the United States even though the starting parents were only a few US cultivars selected from an already narrow genetic base.

The main physiological processes associated with soybean [Glycine max (L.) Merr.] genetic yield progress in central temperate Argentina are largely unknown. This knowledge is critical to identify opportunities to accelerate yield gains via trait‐based hybridization. Our objectives were to: (a) evaluate the influence of biomass accumulation vs. harvest index (HI) in explaining genetic progress, and (b) assess the role of radiation and/or N capture and use efficiency (RUE and NUE, respectively) as drivers of biomass accumulation. We tested 173 cultivars released from 1980 to 2014 in two high‐yielding environments. Additionally, a crop modeling exercise was performed to demonstrate the physiological perception that any genetic increase in RUE would only translate into more yield if there is enough water for the realization of that RUE. Observed genetic progress was 42 kg ha−1 yr−1, or ∼1% yr−1, and was mostly explained by increased aboveground biomass accumulation. This higher biomass of modern cultivars was associated with increased RUE and total N uptake. This suggests that, if residual genetic variation is still present in current soybean cultivars, future genetic improvements should focus on further improving N uptake to increase RUE. Increases in RUE are associated with increased stomatal conductance and water use. Therefore, it would be expected that genetic progress is faster in environments with increased rainfall. Our modeling exercise was consistent with this hypothesis and showed that soybean genetic progress simulated in different locations within a rainfall gradient was positively associated with cumulative seasonal precipitation.