Estimation of nutrient resource quantity of crop straw and its utilization situation in China

Based on agricultural statistics, investigating data of farmer and a number of data published in the literatures, the amount of crop straw and its nutrient resources were estimated in 2006, and the utilization situation of crop straw and its nutrient resources were analyzed in China. The results showed that there was more than 760 million tons crop straws in 2006, which included the amount of nitrogen, phosphorus (P2O5), potassium (K2O) nutrient were 7.76 million tons, 2.49 million tons, 13.42 million tons, respectively. Four kinds of crop straw fate appeared as follow: returned to field (including straight returning and making compost), fuel (including straight burning, setting fire and biogas), fodder and others (including raw material of industry and throwing aside), and the percentage of that were 24.3%, 29.9%, 35.3% and 10.5% in 2006, respectively. The amount of crop straw nitrogen, phosphorus (P2O5), potassium (K2O) nutrient returned to field were 3.05 million tons, 1.76 million tons, 9.67 million tons, respectively. And the rates of the straw nutrient returned to field were 39.3%, 70.5% and 72.0%, respectively. There were great potential of crop straw returned to field, and drastic measures would be needed to reverse the trend of straw burned.