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Estimating Algal Available Phosphorus in Suspended Sediments by Chemical Extraction
Author(s) -
Dorich R. A.,
Nelson D. W.,
Sommers L. E.
Publication year - 1985
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1985.00472425001400030018x
Subject(s) - sediment , extraction (chemistry) , phosphorus , chemistry , algae , environmental chemistry , molybdate , nitrilotriacetic acid , nuclear chemistry , mineralogy , chromatography , botany , geology , inorganic chemistry , biology , paleontology , organic chemistry , chelation
The availability of sediment inorganic phosphorus (P i ) to algae was determined in 28 suspended stream sediments collected from an agricultural watershed in northeastern Indiana by short‐ (2‐d) and longerterm (14‐d) incubations. Unincubated sediment was also analyzed for dissolved molybdate reactive P i (DMRP) and P i extracted by: (i) sequential NaOH and HCl, (ii) sequential NH 4 F, NaOH, and HCl, (iii) nitrilotriacetic acid (NTA), (iv) hydroxy‐Al resin, and (v) total P. Available P (P aa ) measured in sediments by 2‐d and 14‐d incubations with algae averaged 21 and 25% of total sediment P, respectively. Extraction of sediments with 0.1 M NaOH, 0.5 M NH 4 F, sequential 0.5 M NH 4 F + 0.1 M NaOH, NTA, and hydroxy‐Al resin removed an average of 36, 22, 31, 45, and 17% of the total P, respectively. Of the extractants tested, NaOH‐extractable P i was significantly correlated with 2‐d and 14‐d P aa ( r = 0.89*** and 0.95***, respectively) but NaOH extraction removed amounts of P i that exceeded sediment P aa by a relatively constant amount. The results suggest that a single extraction with 0.1 M NaOH can be used to estimate both short‐ and longer‐term P aa in suspended stream sediments derived from noncalcareous soils in the Northcentral USA.