The historical trend of changes in different sources of labor in the productivity of agricultural lands in Iran's wheat production ecosystems (1921-2020)

Traditional agricultural systems and conventional agriculture have major differences from each other. Among these differences, we can refer to the number and different sources of external inputs used to achieve the final production. One of these inputs is the labor issue in Iran's agricultural systems, especially wheat production. The workforce in these systems is provided from the source of human labor, livestock labor and mechanization. The present study was compiled in order to describe the resources used in the physical work that occurred in wheat production ecosystems in Iran and the changes in its cultivated area during a hundred years. For this purpose, the method of energy return on investment was used. The required data were collected from various sources such as the Iranian Statistics Center, the Information and Communication Technology Center of the Ministry of Agriculture, the FAO statistical database, and historical sources. The data were converted into Joules using conversion coefficients and finally, these time series were analyzed using Microsoft Excel 2007 and Minitab® 17.1.0 software. The results of the research indicate an increase in the area under wheat cultivation from an average of 1.5 million hectares at the beginning of the study period to an average of 6.5 million hectares. During this one-hundred-year time period, the final yield of wheat production systems as the amount of work input that has entered the system as an external input (EFEROI) has decreased 37%. Therefore, it is necessary to review and revise the design of labor supply sources for wheat production systems.