Along the roads leading into the small eastern city of Shouguang, workers in hazmat suits stop cars and take passengers’ temperatures. The fever checks are mandatory at offices, too. Whole neighborhoods have been barricaded off to non-residents. All the hotels are shut. Shouguang is 500 miles away from the epicenter of the coronavirus. But the tight precautions reflect the city’s vital importance to China: This is where the country gets its vegetables. The virus crisis is testing China’s ability to feed its 1.4 billion people, one of the Communist Party’s proudest achievements. Cooped up at home and fearful that the epidemic could last weeks or even months, families across China are hoarding provisions, making it harder for shops and supermarkets to keep fresh food in stock. Many places have closed off roads to passing traffic, slowing truck shipments and rising freight costs. […]