Split-plot field experiment with 2-year-old triploid Populus tomentosa clone S1,S6,S8 and S11 as experimental materials and diploid clone S10 as control was carried out in Wei County,Xintai City,Heibei Province.Annual change of soil nutrients in different plantation and tree growth indices of height,DBH and volume were determined.The results showed that soil pH increased and the content of organic matter decreased obviously in a year.Total N,available N,total P,available P,and total K decreased to some extents,while no regulation was found for available K.Different clones had no significant effect on the decline of the soil nutrients.Compared with the control S10,the triploid Populus tomentosa grew much better and took up more soil nutrients,with S8 as the best and followed by S1 and S6.
