If you engage in:

-Use of hired labor.

-Ownership of a mill, a creamery (маслобойня, 'butter-making rig'), other processing equipment, or a complex machine with a motor.

-Systematic renting out of agricultural equipment or facilities.

-Involvement in trade, money-lending, commercial brokerage, or "other sources of non-labor income."

...you just might be a kulak.