Aims The contents of carbon (C), nitrogen (N) and phosphorus (P) in different plant organs and their ecological stoichiometric characteristics are important for understanding of the relationships among soil nutrients in their cycling process. The purpose of this study was to explore the variations of ecological stoichiometry of plant and soil C, N, and P in a jasmine (Jasminum sambac) plantation and their stoichiometric homeostasis under three different treatments.
Methods We set up three treatments: control, straw addition and biochar addition, and measured growth characteristic parameters of jasmine and C, N, P contents in different jasmine organs and in the soil and then analyzed their ecological stoichiometric characteristics.
Important findings Results showed that compared to the control, the straw addition treatment significantly increased the leaf biomass of jasmine by 73.33%, and decreased the soil salinity and soil temperature by 37.04% and 1.41%, respectively. Additionally, the biochar addition treatment significantly increased the plant height, leaf area, leaf and stem biomass of jasmine by 26.11%, 29.42%, 239.59% and 96.04%, while the soil density and soil temperature were significantly lower under the biochar addition treatment than under the control by 18.33% and 1.79%, respectively. Under different treatments, there was no significant difference in leaf or stem C content, or leaf N content. Root and soil C and N contents were significantly higher under biochar addition treatment than under straw addition and control treatments. The P contents of jasmine leaf, stem, root were in the order of biochar addition treatment > control treatment > straw addition treatment, while the soil P content was in the order of biochar addition treatment > straw addition treatment > control treatment. Compared with the control treatment, the biochar addition treatment decreased the C:P of leaf, stem, root and soil, and significantly decreased the N:P of jasmine leaf and stem, while increasing the N:P of root and soil. The overall internal stability of C, N, and P in different organs of jasmine was in the order of C > N > P, and the C:N, C:P and N:P were in the order of N:P > C:P > C:N. In summary, the application of biochar addition increased the absorption and assimilation of N and P by above-ground plants, and further promoted the C sequestration and homeostasis in the plant-soil system.