Basic cation and Al distribution in Ahe soil solution of fertilized maple stand: representativeness of saturation extracts.

Soil solution analysis may provide useful information on nutrition status a nd Al toxicity in soil. Nevertheless, obtaining soil solutions in low-moist ure soils causes a problem. Saturated extracts may act as an alternative fo r getting information on soil solution. Their effectiveness in assessing re presentative base cations and aluminum distribution in soil solution was de monstrated in this study. Saturated extracts, which were obtained from air drying and fresh soil, were compared with the "true" soil solution for base distribution and base/Al ratio. Molar fraction and equilibrium ratio in th e "true" soil solution depended on soil moisture before extraction. Neverth eless, they were less affected by this approach than intrinsic concentratio ns. The results showed that molar fraction and equilibrium ratio in soil so lution can be predicted from the molar fraction or equilibrium ratio in sat urated extracts and soil moisture information, however, saturated extracts obtained from fresh soil were better models. Base/Al ratios in saturated ex tracts were closely dependent on pH extracts but they were not well linked with the same ratio in soil solution.