Input of Cd from agriculture phosphate fertilizer application in China during 2006-2016.

Phosphate fertilizer applications are an important source of soil Cd in China. However, the input of Cd from phosphate fertilizer has always been neglected in China because of its low content. In this paper, we calculated the Cd input from phosphate fertilizer in China during 2006-2016. According to the data, the total phosphate fertilizer consumption and agriculture application rate tended to decrease after 2014. In 2016, the phosphate fertilizer application rate ranged from 12.14 to 99.38 kg/ha with a mean value of 42.70 kg/ha, and excessive fertilizer application occurred in Xinjiang, Henan, and Hubei Provinces. The Cd content in phosphate fertilizer was 0.75 mg/kg based on 1222 samples. The national Cd input from phosphate fertilizer was estimated to be 10.52 tons in 2016, with DAP/MAP being the largest contributor, accounting for 83.31% of the total input. These findings demonstrate the necessity of performing assessments to regulate the utilization of phosphate fertilizer in China, especially in Henan and Xinjiang Provinces.