Slash Pine Response to Nitrogen and Phosphorus on Imperfectly Drained Soil of the West Gulf Coastal Plain

Abstract

AbstractTotal dry weight and nutrient content of 1‐year‐old slash pines (Pinus elliottii var. elliottii Engelm.) responded to combinations of N and P in a pot study with imperfectly drained Coastal Plain soil. Application of either nutrient alone resulted in no growth response. A marked response was obtained with applications equivalent to 50 kg of P and 168 kg of N/ha. Maximum growth as determined by regression analysis was obtained with applications equivalent to 124 kg of P and 232 kg of N/ha.Uptake of individual nutrients increased with N and P levels, but response patterns differed. Nitrogen, calcium, and magnesium uptake corresponded closely to dry‐matter accumulation of seedlings, while P uptake was independent of dry weight. Percentage recovery of applied P decreased with increased P fertilization but improved with addition of N. Recovery of N increased with amount applied and was not affected by P.