Residues and risks of veterinary antibiotics in protected vegetable soils following application of different manures

The protected vegetable farming is a style of high frequent rotation farming which requires a huge amount of fertilizers to maintain soil fertility. A total of 125 surface soils covering from east to west of China were sampled for the analysis of 17 antibiotics in order to identify antibiotics contamination caused by long-term manures application. The results indicate that the agricultural land has accumulated a statistically significantly higher antibiotics concentration than conventional open croplands. The maximum oxytetracycline concentration was 8400 mu g kg(-1), the highest level that has ever been reported for oxytetracycline in soils. The residual concentration is decided by both plant duration and manure type. Short-term (