It Produces income and based on the borrowers tax returns it's either positive or negative just like any other business. 99% of the time your going to know a working farm or ranch the minute you pull up to the property. John Deer tractors, trailers, crops, animals , also a working farm would normally be done by a CG and not on a 1004 form and normally there are multiple buildings, barns, etc. I guarantee you will know a working farm or ranch when you see one

Below is a definition of a hobby farm .
In the U.S., a high proportion of farms might be classed as hobby farms. In 2007, over 40% of farms reported less than $2500 in income and over 10% of farms had less than 10 acres (4.0 hectares) of land. Over 50% of primary farm operators reported that their main income was a job outside of their farm; although, this figure includes some farm operators who do not personally participate in farming and some quite large and productive farms.
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In the US, as farms grow in size, older farms become less economically viable. Some are purchased and most of the land combined with larger nearby farms, however the large farm has little use for the buildings. These can be sold off with only a building lot of real estate, but are much more sale able if a modest area, 5 to 15 acres (20,000 to 60,000 m²) is sold along with them. These are usually snapped up quickly by people with well-paying city jobs who wish to live in the country, or to retirees, who wish to be active as part-time farmers.
Some, especially in developed areas, are used as
truck gardens, with their own produce stands, or a regular stall in a local
farmer's market.