The nitrogen and phosphorus nutrition of white ash (F̲ṟa̲x̲i̲ṉu̲s̲ A̲m̲e̲ṟi̲c̲a̲ṉa̲ L.)

The research reported here is the first endeavor to evaluate the adequacy of Cumberland Plateau and Highland Rim soils in middle Tennessee and northern Alabama for the satisfactory growth and development of white ash. It is part of a research program of the U. S. Forest Service aimed at determining site capability and species adaptability for the Plateau and Rim and providing silvicultural recommendations for the rehabilitation of forest lands. In the first of two experiments seedlings were grown in pots of soil with N and P additions. Mixed Al and A2 horizons from two representative forest soils (Hartsells and Bodine) were tested. The study was a split plot with three replications of each soil (major plots). Minor plots consisted of a complete factorial arrangement of four levels each of N as NH4No3 (0, 168, 336, 504 kg/ha) and four levels of Pas TSP (0, 112, 224, 336 kg/ha). After one growing season growth and N, P, K, Ca, and Mg in the leaves of four seedings per pot were evaluated by ANOVA. Nitrogen and P main effects and their interactions were analyzed by generating linear, quadratic, and cubic components. Seedling biomass and foliar composition were correlated.