The period from the 1930s to the 1980s was marked by far-reaching changes in agrarian structures throughout Latin America. Indeed, it could be argued that the magnitude of change was greater during this half century than in the preceding four centuries. Agricultural production increased dramatically but, by 1990, in almost all Latin American countries, agriculture had become a less important contributor to the gross national product than industry. The social and political significance of agriculture altered sharply. In the 1930s most people in Latin America made their living from the land. Land ownership was still the key to political and economic power at the regional and national level. Many presidents and key political figures were members of the landed elite. By the 1980s those working directly in agriculture were only a quarter of the total labour force. Urban interests and occupations based on industry and services (which included a wide range of financial and administrative services) had become politically dominant.

Crucial changes in the process of agricultural production accompanied this shift in the economic, political and social significance of agriculture and landholding. In the 1930s agricultural production, though usually market-orientated, was largely decentralized. Cropping practices and the organization of agricultural inputs varied from region to region, depending upon ecology, the availability of labour and the nature of the market. This had given rise to a diversity of agrarian structures that generated distinctive regional identities. By the early 1980s agricultural production had become increasingly centralized through the state or large-scale agribusinesses, usually linked to international marketing and financial institutions.