The Environmental Working Group offers a free database that lists farm subsidy payments by county through EWG.org. The database contains farm subsidy payments for every state.
EWG.org offers summary analysis of farm subsidy payments by crop and farm subsidy payments by program. The website also lists top recipients by year. To find subsidy payments for a particular county, search by ZIP code or refine search results by state and county. You can also find farm subsidy payments by congressional district.
The state summary listings rank states according to how many subsidies they have received and the percentage of farms receiving subsidies.