This study aimed to explore intercropping of Hunan millet and soybean in saline-alkali soils. By assessing the photosynthetic characteristics and agronomic performance， the optimal intercropping pattern was identified， providing new solutions for the development and utilization of saline-alkali land. The study included six planting patterns： Hunan millet sole crop （HS）， soybean sole crop （DS）， 2∶2 （H₂D₂）， 2∶4 （H₂D₄）， 4∶2 （H₄D₂）， and 4∶4 （H₄D₄）. The photosynthetic characteristics， agronomic performance， and nutritional quality of Hunan millet were comprehensively evaluated to determine the best intercropping configuration. The results showed that intercropping significantly promoted the growth of both Hunan millet and soybean. Among the intercropping patterns， the land equivalent ratios （LER） of H₂D₄， H₄D₂， and H₄D₄ were greater than 1， with H₂D₄ showing the highest LER of 1.18. Under the H₂D₄ treatment， the net photosynthetic rate （Pn） of Hunan millet was 45.6 μmol·m^-2·s^-1， stomatal conductance （Gs） was 0.0518 mol·m^-2·s^-1， and transpiration rate （Tr） was 3.36 mmol·m^-2·s^-1， all of which were superior to those of the sole crop. Additionally， Hunan millet under the H₂D₄ treatment showed optimal nutritional quality， crude protein content reaching 10.03%， and other indicators such as crude ash， crude fat， acid detergent fiber， neutral detergent fiber， and relative feed value all performed well. Principal component analysis further confirmed that the H₂D₄ pattern performed the best overall. This intercropping configuration promoted an ideal light environment within the plant canopy， leading to enhanced both yield and quality of Hunan millet and soybean.

Hunan millet  /  Intercropping  /  Production performance  /  Nutritional quality