Vol14 No.12: 2420-2431
【Title】Impacts of soil properties on phosphorus adsorption and fractions in purple soils
【Author】XIAO Yi1; TANG Jia-liang1*; WANG Ming-kuang2; ZHAI Long-bo1; ZHANG Xi-feng1
【Addresses】1 Key Laboratory of Mountain Environment Evolution and Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China; 2 Department of Agricultural Chemistry, National Taiwan University, Taipei 10617, Chinese Taipei
【Citation】Xiao Y, Tang JL, Wang MK, et al. (2017) Impacts of soil properties on phosphorus adsorption and fractions in purple soils. Journal of Mountain Science 14(12). https://doi.org/10.1007/s11629-017-4545-2
【Abstract】Information on phosphorus (P) adsorption and its impacts on the redistribution of the P fraction in soil profiles are important for environmental management under intensive agricultural practices. To clarify the dominant factors influencing soil phosphorus adsorption in an Entisol (locally known as purple soil), P adsorption experiments were conducted in Sichuan Basin of southwestern China for cropland and woodland soils with acidic, neutral and calcareous origins throughout their profile. After various doses of P were added during incubation experiments, soil P fractions were also analyzed. The results showed that there were no significant differences in Fe-oxides and P adsorption along the vertical gradients. Agricultural practices and lower pH conditions reduced the P adsorption capacity of purple soils throughout the soil profiles. For acidic and neutral purple soil profiles, the P adsorption capability was mainly influenced by Fe-oxides and soil texture. Ca-bound P and Fe-Al-bound P represented the majority of the total inorganic P of calcareous soils. There was a saturation of adsorption capacity by sesquioxide and a high risk of dissoluble reactive P (NH4Cl-P) being released out of the soil profile in acidic and neutral purple soils after the greatest P addition, indicated by the higher proportions of NH4Cl-P (over 40%) and decreasing Fe-Al-P fraction. P fractions migrated with greater difficulty in calcareous purple soil profiles as Ca-P fraction peaked over 65% when adding a P dose at or greater than 80 g P kg-1, indicating the high potential of P adsorption. The X-Ray Diffraction analysis also verified the formation of brushite. Adaptive management practices should be designed to alleviate P losses for acidic and neutral purple soils.
【Keywords】Agroecology; Soil parent material; Fe-oxides; Phosphorus adsorption; Incubation experiment; Phosphorus fraction