US leads the world in farm productivity per labour force attributable to agriculture Labour force  by occupation for each country is available at httpwwwciagovciapublicationsfactbookfieldshtml Multiply this by labour force of that country which is available at httpwwwciagovciapublicationsfactbookrankorderrankhtml The result is the portion of labour force attributable to agriculture Now divide the agricultural output by this number to get the  value of farm productivity per labour per year Among the top five nations based on agricultural output US is way ahead on top    US   Japan   Brazil   China   India  Smaller economies may have higher productivity than US but they are insignificant on a global scale plus in practicality small agri projects with unusually high yields have had mixed or no success when scaled up to large commercial markets