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Phosphorus Retention in Coastal Plain Forest Soils: II. Significance to Forest Fertilization
Author(s) -
Ballard R.,
Pritchett W. L.
Publication year - 1974
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1974.03615995003800020039x
Subject(s) - slash pine , soil water , phosphorus , chemistry , human fertilization , zoology , nutrient , pinus <genus> , botany , agronomy , biology , ecology , organic chemistry
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 NH 4 OAc (pH 4.8), 0.03 N NH 4 F + 0.025 N HCl, or 0.03 N NH 4 F + 0.1 N 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 NH 4 OAc, 0.03 N NH 4 F + 0.025 N HCl, 0.03 N NH 4 F + 0.1 N HCl, and 0.05 N HCl + 0.025 N H 2 SO 4 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.