Answer: 

The United States Department of Agriculture's (USDA) National Agricultural Statistics Service (NASS), Economic Research Service (ERS), and other departments provide a number of statistical releases, prices, and reports that detail the US agriculture sector. Cornell's Mann Library hosts many of these resources on the Economics, Statistics and Market Information System, an easy to use site that consolidates various agency reports and statistics in one place. These include things like:

  • Crop reports
  • Prices for crops, labor, land value, grazing fees, and other related agricultural expenses.
  • Data and reports on aquaculture, genetically modified crops, and textiles.

For agriculture in other countries, look to government agencies and NGOs such as Foreign Agricultural Service (FAS), UN Comtrade, and OECD as well as the government agencies of the specific nations you are looking at. The library has a number of fee-based resources that make it easy to search for data across countries, such as Passport and CEIC.