Defra Statistics
Defra produces useful statistics annually on the structure of the industry, which you can find at https://www.gov.uk/government/statistical-data-sets/structure-of-the-agricultural-industry-in-england-and-the-uk-at-june
The Agricultural Price Indices are available at https://www.gov.uk/government/statistics/agricultural-price-indices giving annual prices for key agriculture products and inputs since 1988, and monthly data since 2011.
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