Newly transplanted Larix olgensis Henry stock with greater root biomass has higher early nitrogen flux rate

AbstractDuring the early time after transplanting, the ability of nitrogen (N) uptake in roots of tree stocks is crucial to their future performance. However, it is not clear about the relationship between size or nutrient reserves in nursery-cultured tree seedlings and root N flux (N flow within or out of root) after transplanting. In this study, we pre-fertilized Changbai larch (Larix olgensis Henry.) seedlings with three top-dress applications [N-phosphorus (P)-potassium (K), 20-4-10] at rates of 0 (control), 31.58 (E-Low), 200 (E-Medium), and 525.08 (E-High) kg N ha–1 to different levels of nutrient storage during the first growing season. After being graded into large and medium sizes, stock N status was indicated to be discriminative in response to pre-fertilization by vector analysis. Overwinter stocks were transplanted into aerated distilled water or nutrient solution to detect root N influx or N efflux, respectively, at the second and fourth weeks under laboratory conditions. Larger stocks had hi...