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A Comparison of Soil Sulfur Extraction Methods
Author(s) -
Ketterings Quirine,
Miyamoto Chie,
Mathur Renuka Rao,
Dietzel Kevin,
Gami Sanjay
Publication year - 2011
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/sssaj2010.0407
Subject(s) - soil water , extraction (chemistry) , chemistry , soil test , gypsum , sulfur , detection limit , inductively coupled plasma , analytical chemistry (journal) , inductively coupled plasma atomic emission spectroscopy , mineralogy , environmental chemistry , environmental science , soil science , chromatography , materials science , metallurgy , organic chemistry , plasma , physics , quantum mechanics
There are currently no field calibration data for interpretation of soil S tests in the U.S. Northeast and limited data elsewhere. Given the reduction in the S deposition rate during the past decade in the Northeast, it is important to evaluate the potential for soil testing as a tool for S management in the region. An incubation study was conducted to compare: (i) the accuracy and effectiveness of six S extraction methods to identify an increase in available S; and (ii) S detection in solution using inductively coupled plasma atomic emission spectroscopy (ICP–AES) at 182 nm with turbidimetric determination of S using BaCl 2 ×2H 2 O and a spectrophotometer at 420 nm. The six extraction solutions were 1.0 mol L −1 NH 4 OAc, 0.016 mol L −1 KH 2 PO 4 , 0.01 mol L −1 Ca(H 2 PO 4 ) 2 , 0.01 mol L −1 CaCl 2 , Morgan, and the Mehlich‐3 solution. Four New York soils were treated with six S rates (0, 28, 56, 84, 112, 168 kg ha −1 ) applied as gypsum and incubated for 4 wk (in the dark, at room temperature, 75% of field capacity, four replications). Sulfur test results correlated with S fertilizer application for all extraction and detection methods; however, the 0.01 mol L −1 CaCl 2 extraction with ICP–AES detection of S in solution was best correlated with S added (highest r 2 , smallest RMSE across all four soils), the regression equation had the largest slope, and this method showed the greatest consistency between the two detection methods. We conclude 0.01 mol L −1 CaCl 2 extraction with ICP–AES detection of S is most promising and should be evaluated in field trials.