Agriculture is the backbone of the economy of Uzbekistan and cotton is the main export item of the country. Uzbekistan is now the world's second-largest cotton exporter and fifth largest cotton producer. The mining industry of Uzbekistan has added to the national output of the country. Gold, coal, copper, zinc, lead, fluorspar, uranium, tungsten and molybdenum are the main mineral resources of the country. Cotton, gold, natural gas, oil, fertilizers, metals, textiles, food products, machinery, and automobiles are the major exports. Imports include machinery and equipment, foodstuffs, chemicals, and metals. The main trading partners are Russia, China, South Korea, Kazakhstan, and Turkey.