Phosphorus Leaching from a Gley Meadow Soil in Relation to Soil Fertility Level and Fertilizer Application

The influence of fertilizer application on leaching of phosphorus in a gley meadow soil at low-, medium and high-fertility levels was studied using unsaturated intact soil columns. The soil column at each fertility level received three fertilization treatments (control [CK], manure [M] and chemical fertilizer [F]). The results showed that the leaching loss of DTP from the soil column was induced by the P input from either manure or chemical fertilizer application, and the extent of leaching loss of P was also positively related to the soil fertility level. In addition, the DTP concentrations in the leachates from the fertilization treatments all exceeded the critical value for water eutrophication (0.02 mg P/L). This suggests that applications of manure and chemical fertilizer at proper rates with close consideration of the soil fertility level are essential to reduce the leaching loss of DTP to the environment.