All data used by American Farmland Trust to create this chart is from published sources. Wherever possible, we've included an address so you can use the same sources for your research.
We used two pieces of information to make the chart: the market value of agricultural products sold in each county, and the Urban Influence Code of each county.
Two databases were used to get this information:
- 1997 U.S. Census of Agriculture, CD-ROM database
- 1997 USDA Economic Research Service Urban Influence Codes
Working from the 1997 U.S. Census of Agriculture CD-ROM database, we used five fields of data to determine market value by food group:
- Vegetables were calculated from database field 020053 and include vegetables, sweet corn and melons.
- Fruit were calculated from field 020055 and include fruits, nuts, and berries.
- Meat was calculated from field 010023 and includes livestock, poultry and their products.
- Dairy was calculated from field 020065 and includes livestock and poultry dairy products.
- Grain was calculated from field 020031 and includes grains.
From the 1997 Economic Research Service Urban Influence Codes, we used one field of data:
Each county has an Urban Influence Code, placing the county into one of nine mutually exclusive groups. These groups classify metropolitan counties by the size of their metro area, and nonmetropolitan counties by their adjacency to each size of metro area and by the size of their own largest city or town. These nine codes are:
1 Counties in large metropolitan areas of one million or more residents
2 Counties in small metropolitan areas of less than one million residents
Adjacent to a large metro area and
3 Contains all or part of its own city of 10,000 or more residents
4 Does not contain any part of a city of 10,000 or more residents
Adjacent to a small metro area and
5 Contains all or part of its own city of 10,000 or more residents
6 Does not contain any part of a city of 10,000 or more residents
Not adjacent to a metro area and
7 Contains all or part of its own city of 10,000 or more residents
8 Contains all or part of its own town of 2,500 to 9,999 residents
9 Totally rural, does not contain any part of a town of 2,500 or more residents
AFT regrouped the nine codes into one of two categories:
- Urban Influenced county = counties with an urban influence code of 1, 2, 3, 4, or 5.
- Not Urban Influenced county = counties with an urban influence code of 6, 7, 8, or 9.
The two databases were then combined to determine the market value of agricultural products sold from each food group in each Urban Influenced county using the county re-grouping. This allowed us to determine the market value of each food group in Urban Influenced Counties. This is the information you see on the graph.