By Chris M. Boyd
The IPUMS International Historical Geographic Information System (IHGIS) provides subnational data from agricultural and population and housing censuses from around the world. The agricultural census data cover a wide range of information on agricultural inputs, labor, production, and more, which can be used to explore a variety of research questions. IHGIS data can help understand, for instance, which factors contribute to better crop productivity, including the role of fertilizer use. Researchers have used agricultural census data at the subnational level to analyze the negative relationship between farm size and fertilizer overuse in China1; the relationship between maize yield, farm size and fertilizer and irrigation use in Mexico2; the use of chemical fertilizers in direct market farms in the U.S.3; and the environmental sustainability of using fertilizers, insecticides and pesticides in Pakistan4.
To date, IHGIS has released Agricultural Census tables for ten countries (see https://ihgis.ipums.org/dataset-descriptions), including seven developing countries in Africa and the Pacific Islands. These seven datasets include information about fertilizer use, though each measures it in a different way (see Table 1). Despite the differences, these data can reveal broad patterns in the use of fertilizer by farmers among these countries.