Spatio-temporal effects of fertilization in Anhui Province, China

In order to understand the status and trends in spatio-temporal variations and effects of using inorganic, chemical fertilizers, indexes of hazards of fertilization, including the Fertilization Environmental Hazard Index (FEHI), and fertilization environmental safety threshold were developed and used to evaluate potential for hazards of fertilization and thus sustainability of the use of artificial, exogenous inorganic fertilizers in Agriculture in China. An example case for Anhui Province, China, is presented. Anhui Province is one of the primary agricultural provinces in China, with serious eutrophication of surface waters due to non-point source pollution from application of fertilizer in agriculture. The FEHI increased from 0.57, which represented little hazard in 1990 through 0.65 (medium hazard) in 1995 to 0.77 (serious hazard) in 2012. Based on increases in this index and current trends in use of chemical fertilizers, it is predicted that rural aquatic environments of Anhui Province will continue to be affected by cultural eutrophication. Among 16 regions, there were two regions in Anhui Province classified as being at extreme hazard due to over-fertilization, seven regions being at serious hazard and six regions being at moderate hazard. Extreme hazard of pollution due to excess nitrogen (N) was predicted for two regions, and hazard was extreme for five regions due to excess phosphorus (P), and the predicted hazard from potash (potassium; K) was serious for eight regions.