Abstract: Soil samples were collected from the rotation land, grassland, forestland, and dry land in Quanzhou City to study the soil phosphorus (P) sorption-desorption characteristics under different land use. Langmuir isotherm equation could well describe the soil P sorption characteristics. The soil P sorption capacity of rotation land and dryland was higher than that of grassland and forestland, and the soil P loss risk was in the order of rotation land > grassland > forestland > dry land. The soil P sorption constant and maximum buffering capacity were in the sequence of dry land > rotation land > forestland > grassland, and thereby, the recommended P application rate should be in accordance with the sequence. The soil P desorption rate of rotation land and grassland was higher than that of dry land and forestland, and the soil P buffering capacity was dry land > forestland > rotation land > grassland. Principal component analysis revealed that the mean P desorption rate, easily desorbable P, P sorption index, and equilibrium P concentration could best reflect the potential of soil P loss, and be used as the main indices to assess the potential of soil P loss.

Key words: Modular growth, Moisture, Grey correlation