The most consistent source of data on agriculture is provided by the US Census of Agriculture administered by the United States Department of Agriculture. The Census of Agriculture occurs once every five years in years ending with 2 or 7, and is a complete count of U.S. farms and the people who operate them. It includes large or small properties in rural or urban settings in which $1,000 or more of plant or animal products were raised and sold, or normally would have been, during the Census year. The Census of Agriculture also looks at land use, land ownership, operator characteristics, production practices, income, and expenditures.
The most current US Census of Agriculture data (2017), for Pennsylvnia Counties can be accessed through the United Stated Department of Agriculture website.
The 2017 Census of Agriculture can be accessed from the The National Agricultural Statistics Service website.
Information on agriculture is also available from the Center for Rural Pennsylvania.
Economic inforation on agriculture is available from PAWorkStats which is the website for the Center for Workforce Information and Analysis.