Plant and Soil

, Volume 85, Issue 1, pp 11–21

Correlations among indices of forest soil nutrient availability in fertilized and unfertilized loblolly pine plantations

  • S. C. Hart
  • Dan Binkley

DOI: 10.1007/BF02197796

Cite this article as:
Hart, S.C. & Binkley, D. Plant Soil (1985) 85: 11. doi:10.1007/BF02197796


Various laboratory indices of N and P availability in forest soils correlated poorly among themselves and with on-site ion exchange resin (IER) estimates in both unfertilized and N+P fertilized loblolly pine plantations. IER nutrient availability estimates had greatest within-site variability than laboratory indices. Net nitrification was minimal in laboratory incubation of the mineral soil despite high rates of ammonification. In contrast, IER NO3−N values were usually of the same magnitude as IER NH4−N values. In both fertilized and unfertilized stands, at least one N availability index was negatively correlated with at least one P index. Soil N and P availabilities were generally higher on fertilized plots than on unfertilized plots 3.5 years after fertilization, and IER estimates showed the greatest number of plots with increased levels. The greater ability of the IER method to distinguish between fertilized and unfertilized plots indicated the method was affected by on-site factors that the laboratory methods do not assess.

Key words

Aluminium Ammonium Ion exchange resin Nitrate Phosphate Pinus taeda 

Copyright information

© Martinus Nijhoff/Dr W. Junk Publishers 1985

Authors and Affiliations

  • S. C. Hart
    • 1
  • Dan Binkley
    • 1
  1. 1.School of Forestry and Environmental StudiesDuke UniversityDurhamUSA
  2. 2.Graduate Group in Soil ScienceUniversity of CaliforniaBerkeley

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