The Nutrient Pool of Five Important Bottomland Hardwood Soils

Abstract

Heretofore, with the exception of N, the concentration of total nutrients and the amount of variation in nutrient concentrations among and within soil series and depths within the rooting zone of forested alluvial soils of the South was unknown. Information about total nutrient concentrations is important in studying the danger of nutrient depletion posed by total tree harvest and other forms of intensive management. In this study, five important alluvial forest soils were sampled on each of five sites, and the samples were analyzed for total N, P, K, Mg, and Ca. Available nutrient levels were determined as well. Soil series was a significant source of variation for all nutrients (p = 0.95). Nutrient concentration varied significantly among sites within soil series in most cases. Total N, P, and Mg also varied by depth. The available nutrient concentrations of all five nutrients were significantly correlated with their respective total nutrient concentrations. These alluvial soils are high in nutrients; potassium content is particularly high (8-19 g/kg). Nutrient depletion resulting from withdrawals of nutrients in whole-tree harvests will not occur for several rotations in the soils tested. However, to reduce the risk of depletion of sites with unexpectedly low nutrient reserves, the soil should be tested, and when needed, maintenance fertilizer should be applied or less intensive harvests prescribed.

Citation

Francis, John K. 1988. The Nutrient Pool of Five Important Bottomland Hardwood Soils. Res. Note SO-327. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 5 p.