Reclamation of salinity-affected land for intensive agricultural production represents a highly promising pathway towards feeding our increasing global population. Nonetheless, biodiversity and ecosystem service responses to agricultural intensification in desalinized landscapes remain poorly understood. In our study, we analyzed long-term diversity responses of carabids as important pest control agents to agricultural intensification in desalinized landscapes by comparing data from 1997 and 2014, and we analyzed the potential role of field-margins as beetle refuge habitats. Despite agricultural intensification, carabid species richness increased significantly following desalinization, with this increase being chiefly limited to field margins. Carabid assemblages also showed a dramatic temporal species turnover, leading towards a species-rich, homogeneous community dominated by generalists. Therefore, we believe that desalinization triggered positive regional diversity responses despite simultaneous agricultural intensification, with semi-natural field margins playing an increasingly important role as local diversity hotspots. Nonetheless, the highly uniform composition of the generalist beetle assemblages and its potential implications for ecosystem functioning require further scrutiny, and the targeted management of semi-natural habitats appears crucial to optimize farmland biodiversity and associated ecosystem services in desalinized agricultural landscapes.