A high-yield method for quinoa and sunflowers intercropping in saline-alkali soil including steps of soil physical improvement, mechanical improvement, chemical improvement, and sowing. The physical improvement is as follows:
A central elevated slope with lower surrounding edges is formed on the field surface. Embankments are constructed along the lowered peripheral edges to enclose the field, and drainage ditches are excavated outside these embankments. The field is rapidly flood-irrigated until the water level reaches 20 cm above the ground surface, maintaining this water level for 10-15 hours to ensure infiltration to at least 30 cm below the surface. Simultaneously, dig out drainage outlets in the peripheral embankments to enable synchronized discharge of field water into the surrounding drainage ditches for salt-removing. This invention first reduce soil salinity by salt-removing in the field, then implements mechanical and chemical improvements to control salinity to meet technical requirements, followed by sowing. This prevents quinoa and sunflower seeds from failing to germinate due to excessive salinity.