PetroChina, China Petroleum & Chemical, China National Offshore Oil, and Shaanxi Yanchang Petroleum were required by the General Office of Ministry of Commerce of China on April 23, 2008 to increase their production capacity in diesel oil, in face of the serious shortages of diesel oil for agricultural use.
Agricultural costs increased in the wake of rising prices of agricultural production means in 2008. In the central Chinese province of Hunan, agricultural costs soared 40% to 50%. The cost in diesel oil surged more than CNY 400, and that in potash fertilizer increased CNY 150 per ton.
Looming prices of agricultural production means during the spring planting have prompted the Chinese government to take several measures to stablize them, in a bid to insure the grain production and valorize the nation's prices. For instance, as for the fertilizer, the government adjusted its export tariffs, fixed its price, and blocked its export volume, in order to assure the domestic supply. 
