A leaching experiment was conducted using soil column simulation to investigate the release andtransferring characteristics of phosphorus in three soils of Yangling Demonstration Zone

Shaanxi Provinceunder erosion effects of five acid rain gradients.The results showed that acid rain resulted in soil acidificationto some extent

which was controlled by the pH value of the acid rain

soil type

soil pH value

cation exchange capacity and organic matter content.The soils could be ranked in terms of acid rain buffering capacityin a descending order as humus layer>parent material layer>adhesive layer.With the increase of total leaching amount by acid rain

the total soil phosphorus release amount increased with a decreasing leaching rate.Soil phosphorus loss amount achieved the maximum value with acid rain that has a pH value of 5.The soilscould be then ranked in terms of either the cumulative soil phosphorus release amount or the leaching rate ina descending order as humus layer>adhesive layer>parent material layer.Acid rain showed the strongesterosion effect on phosphorus of the humus layer.The acidification in the parent material layer and the adhesive layer occurred mainly in surface

while the acidification in the humus layer mainly occurred in the lowerpart.The most severe acidification by acid rain was found in the humus layer.Long-term acid rain leachingcould lead to soil phosphorus loss and causes soil nutrient impoverishment.