Sorghum bicolor (L.) Moench is still relatively unknown in Switzerland, with only around 400 ha under cultivation. As a result, basic cultivation techniques have hardly been researched or standardized to date. As a C4 plant adapted to dry conditions, sorghum may contribute to climate-resilient cropping systems. Its high biomass production and gluten-free grain make it suitable for both forage and human consumption. In a three-year trial (2022–2024), four sorghum, one maize variety, and a maize-sorghum mixture were investigated in Zurich (CH). Three different row spacings (37.5 cm, 50 cm, 75 cm) and three sowing densities were tested. The aim of the study was to evaluate the response of the sorghum varieties to different row spacings and sowing densities by measuring various agronomic parameters such as lodging, dry matter yield, and the forage quality of the harvested crop, and to compare them with maize. The results show that the choice of variety has the greatest impact on dry matter yield and forage quality. Biomass varieties such as ES Biomass and KWS Zerberus achieved higher dry matter yields than CSSH-45 and ES Athena, but they had lower net energy of lactation (NEL) values and poorer organic substance digestibility (DOM) compared to CSSH-45 and ES Athena. Increasing sowing density led to higher dry-matter yields, but partly at the expense of stand stability. Altering the row spacing had no significant effect on either dry matter yield or forage quality (NEL and DOM).
