HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Ige, D. V. Articles by Flaten, D. N. Search for Related Content PubMed Articles by Ige, D. V. Articles by Flaten, D. N. Agricola Articles by Ige, D. V. Articles by Flaten, D. N. Related Collections Sorption/Exchange Nutrient Cycling Soil Chemistry

SOIL CHEMISTRY

Direct and Indirect Effects of Soil Properties on Phosphorus Retention Capacity

Dep. of Soil Science, Univ. of Manitoba, Winnipeg, MB, Canada R3T 2N2

^* Corresponding author (akinremi{at}ms.umanitoba.ca).

Phosphorus retention ability of soil has been predicted from different combinations of soil properties as a result of significant correlations between these variables. However, a significant correlation between P retention capacity and a soil property does not necessarily imply a significant direct effect of the soil property on P retention. The objective of this study was, therefore, to evaluate the direct and indirect influence of soil properties on P retention capacity of neutral to calcareous soils of Manitoba (Canada). One hundred fifteen archived surface soil samples representing major soils of Manitoba were used for the study. The P retention index (PRI) of these soils was determined by the single-point adsorption method. The relationships between P retention and soil properties were evaluated by correlation analyses while the direct and indirect influences of these soil properties on P retention were evaluated using the path analysis procedures. Significant correlations (p = 0.05) were observed between PRI and pH; CO₃^2–; organic C; sand content; silt content; clay content; exchangeable Ca (Ca_Ex); exchangeable Mg (Mg_Ex); cation exchange capaciaty (CEC); Mehlich-3 extractable Ca (Ca_M3); Mehlich-3 extractable Mg (Mg_M3); and oxalate extractable Al (Al_Ox). However, path analysis showed that only Ca_M3 D = 0.62), Mg_M3 (D = 0.26), and Al_Ox (D = 0.21) had significant direct effects (p = 0.05) on PRI. The significant effect of sand (soil texture) was due to the indirect influence of Ca_M3. Our results show that the PRI for the neutral to calcareous soils of Manitoba is best predicted from Ca_M3, Mg_M3, and Al_Ox. Similar analysis conducted to relate the classical Langmuir adsorption maximum with the properties of a subset of soils also showed Ca_M3, Mg_M3, and Al_M3 as the soil variables that had significant direct effects on soil's P retention.