Abstract: 【Objective】Soil phosphorus release to the water bodies in the upland fields of yellow soil areas and influencing factors was studied in Guizhou province. 【Method】Adopting by the no boundary runoff little section, pot and simulating experiment.【Result】The results showed that the content of dissolved active P of surface runoff from various upland fields of yellow-soil were significantly different, which the concentrations of dissolved active P of runoff correlated with the contents of available-P, amorphous oxides of Al, and organic matter in the soils. The amount of soil phosphorus release to the water bodies affected by the level of applying P fertilizer and the process of maize growth. When the fertilizer application rate was from 150 to 900 kg·ha-1 (P2O5) in the soil with high P level, the average contents of dissolved active P in the penetrated-water of the soil increased from 0.020 mg·L-1 to 0.137 mg·L-1. The amount of soil phosphorus release to the water bodies also affected by environmental factors. The amount of soil phosphorus release significantly increased on the conditions that the temperature was 30-35℃, water/soil ratio was 15﹕1 to 25﹕1, submerged-time in water was 12-18 h and pH value of acid rain was 3.82-3.73. 【Conclusion】The content of dissolved active P of surface runoff from various upland fields of yellow-soil was significantly different, which significantly positive and negative correlated with available-P, and amorphous oxides of Al and organic matter in the soils, respectively.

Key words: Upland fields of yellow soil, Soil P release, Dissolved active P of runoff, Influencing factors