In order to limit illegal migration while maintaining the labor supply in its key agriculture sector, Spain uses circular migration programs to bring in seasonal workers from other countries, such a Morocco. Recently, Spain has decided to extend its circular migration program to Senegal as a means to address the decades of issues with illegal migration from the country. The selection of workers for this program will be at the discretion of the Senegalese authorities, and then they will relocate to Spanish farms during the harvest season. One of the main challenges with these programs though is ensuring that the workers return back to their home countries after their contracts are up.
See "In order to meet the demand for labor during harvest season in the agriculture sector, Spain extends its circular migration program to Senegal ", Belen Carreno, Reuters, March 2, 2023