Aerial photo taken on May 18, 2021 shows the salt ponds at Binhai Township, Zhanhua District, Binzhou City of east China's Shandong Province. Workers have started harvesting "spring salt" from the 600,000-mu (40,000 hectares) of salt fields at Binhai Township. The total output is expected to hit 500,000 tons when the harvest work concludes by the end of June. (Xinhua/Fan Changguo)