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

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ballard, R. Articles by Pritchett, W. L. Search for Related Content PubMed Articles by Ballard, R. Articles by Pritchett, W. L. Agricola Articles by Ballard, R. Articles by Pritchett, W. L.

Phosphorus Retention in Coastal Plain Forest Soils: II. Significance to Forest Fertilization¹

ABSTRACT

Phosphorus retention of 42 forest soils collected from the US Southeastern Coastal Plain was found to be significantly correlated with Al and Fe extracted by soils tests for available phosphorus. Aluminum provided better indices of P retention than Fe extracted by these tests and it accounted for more than 81% of the variation in P retention in the case of the NH₄OAc (pH 4.8), 0.03N NH₄F + 0.025N HCl, or 0.03N NH₄F + 0.1N HCl tests.

Concentrations of Fe and Al in the foliage of 4-year old slash pine (Pinus elliottii Engelm. var. ‘elliottii’) growing on these soils were significantly correlated with soil P retention. However, foliar Fe, the most closely correlated, accounted for only 26% of the variation in P retention.

Retention of P from concentrated superphosphate applied at the equivalent 56 or 224 kg P/ha 4 years previously to young slash pine was measured to 20 cm depth at 10 sites, and ranged from –14 to +125%. Retention was almost independent of application rate. Extractable Al values corresponding to 50% retention of the applied P were 40, 330, 400, and 120 ppm for NH₄OAc, 0.03N NH₄F + 0.025N HCl, 0.03N NH₄F + 0.1N HCl, and 0.05N HCl + 0.025N H₂SO₄ extractions, respectively. It is proposed that in the interest of maintaining long-term growth responses and minimizing possible pollution effects, these values be used for delineating soils of low P retention where less soluble sources of P, such as rock phosphate, should be used if P fertilization is required.

¹ Contribution from the Soil Sci. Dep., Florida Agr. Exp. Sta., Gainesville, as Journal Series Paper no. 4988.

² Graduate Assistant and Professor of Soils, respectively, Univ. of Florida. Senior author is Scientist, Forest Research Inst., Rotorua, New Zealand.

Received for publication July 25, 1973. Accepted for publication November 2, 1973.