There's a little bit of apples and oranges here. Farm output is 1% of GDP and farm employment is at about a similar level (see https://www.bls.gov/ooh/farming-fishing-and-forestry/agricultural-workers.htm). I think the topline number should be $1T across all ag+food (see https://www.ers.usda.gov/data-products/ag-and-food-statistics-charting-the-essentials/ag-and-food-sectors-and-the-economy/)