Provincial grain yields in Spain, 1750-2009

This paper estimates the yields for five grains in 33 provinces of Spain in the mid-18th century. The results show that yields were higher in the north of the country, and that the most fertile provinces of Spain were not far behind the most advanced agricultural regions of the world. Average wheat yields in Spain remained stagnant between 1750 and the late 19th century when they doubled, only to remain stagnant again until the modernisation of the primary sector in the 1960s. Our results show that, in the very long run, yields between provinces tended to converge, and this was the case until the 1960s when the traditional differences in provincial yields began to disappear. The use of artificial fertilisers or new wheat strains were key improvements that helped low yield provinces to break with severe natural constraints such as lack of rainfall or low-quality soils.