RESPONSES OF THE GROWTH AND NUTRIENT STOICHIOMETRY IN RICINUS COMMUNIS SEEDLINGS ON FOUR SOIL TYPES*

Responses of the growth and nutrient stoichiometry in Ricinus communis seedlings were assessed by culturing seedlings on the plant acid purple soil (ACS), alkaline purple soil (ALS), yellow soil (YS) and red soil (RS). The results showed that soil types may significantly affect the basal diameter, total biomass, root-shoot ratio, C, N and P contents, P and K accumulation, N allocation ratio and N and P use efficiency in R. communis seedlings (P 0.05). However, there were no significant differences in terms of the root length, specific leaf area, robustness and C and K use efficiency (P 0.05). The order of seedlings??? height and basal diameter were ALS>RS>ACS>YS, and the order of total biomass was ALS>ACS>RS>YS. The N, P contents and total accumulation of C, N, P and K in the stem were the highest in ALS. The use efficiency of C, N, P and K in different soil types was C>K>P>N, and the N and P use efficiency in purple soil was significantly higher than those of in YS and RS. The roots, stems, leaves and total N:P ratio of R. communis seedlings were far lower than 14, indicating that the seedlings growth on four soil types was severely restricted by nitrogen. Compared with the other three soil types, ALS was more suitable for the early cultivation management of R. communis seedlings, and the appropriate increase of nitrogen fertilizer was conducive to the more efficient growth and development of R. communis seedlings. The results will help to provide theoretical basis and reference for site selection, cultivation and fertilization management of R. communis.