Abstract Soybean Glycine max (L.) Merr. production in the lowlands of Rio Grande do Sul, Brazil, covers more than 50% of the area traditionally cropped with irrigated rice. However, soybean yields in lowland fields average 3.0 Mg ha − 1 , which is well below the potential yield (6.2 Mg ha − 1 ) estimated for highland areas. This study examined management practices affecting yield variability in 240 lowland fields over six growing seasons (2015–2016 to 2021–2022). Data were collected through on‐farm surveys and analyzed to evaluate the impact of key agronomic factors. The results show that sowing date, crop rotation, liming, tillage, and fertilization are the main factors influencing yield. Sowing between October 20 and November 17 resulted in the highest yields (approximately 5 Mg ha − 1 ), while later sowing reduced yield by 44–68 kg ha − 1 per day, depending on the maturity group. Soybean monoculture yielded more than soybean–rice ( Oryza sativa L.) rotation, likely due to herbicide carryover and soil compaction. Annual liming improved soil pH and increased yields compared to less frequent applications. No‐tillage systems increased yield by 339 kg ha − 1 compared to conventional tillage, indicating benefits in soil structure and moisture retention. Fertilizer use, especially P 2 O 5 and K 2 O, was higher in the most productive fields, although excessive application was less effective in compacted soils. These findings provide practical strategies to reduce the yield gap in lowland soybean systems and support more sustainable and cost‐effective agriculture. Better management can align yields with regional potential and reduce environmental impacts, contributing to the advancement of lowland agriculture globally.
Tagliapietra et al. (Sun,) studied this question.