Four hundred inquiries from American farmers poured in after a single interview. Not for a John Deere. Not for a Case IH. For a tractor built in Alberta with a remanufactured 1990s diesel engine and zero electronics. Ursa Ag, a small Canadian manufacturer, is assembling tractors powered by 12-valve Cummins engines — the same mechanically injected workhorses that powered combines and pickup trucks decades ago — and selling them for roughly half the price of comparable machines from established brands. The 150-horsepower model starts at $129,900 CAD, about $95,000 USD. The range-topping 260-hp version runs $199,900 CAD, around $146,000. Try...