Phosphorus in Morgan Soil Test Extracts Measured By Molybdate Colorimetric and Inductively Coupled Plasma Spectroscopy Methods


TitlePhosphorus in Morgan Soil Test Extracts Measured By Molybdate Colorimetric and Inductively Coupled Plasma Spectroscopy Methods
Publication TypeJournal Article
Year of Publication2017
AuthorsYoung, EO, Ross, DS, Hoskins, BR
JournalCommunications in Soil Science and Plant Analysis
Volume48
Start Page2434
Issue20
Pagination2434 - 2446
Date Published2017/12
ISSN0010-3624
KeywordsInductively coupled plasma, Morgan soil test, phosphorus
Abstract

Colorimetric P determination mainly reflects inorganic P, whereas inductively coupled plasma spectroscopy (ICP) measures all P in solution. We compared Morgan extractable P for ICP (MP-ICP) and colorimetry (MP-Color) using dairy farm field samples (0 to 20 cm) across northern New York (n = 250) and hayfield transect samples (0–15, 15–30, 45–50 cm; n = 164). Soil organic matter, pH, and extractable cations were also measured. Mean ratio of MP-ICP: MP-Color was 1.46 and differed significantly among Morgan P categories, ranging from 1.89 for low to 1.06 for very high. The numeric difference between MP-ICP and MP-Color ranged from 0 to 12.9 mg kg−1. Organic matter, Al, and pH jointly accounted for 55% of the variability between methods across samples. Fertilizer P recommendations differed based on the two methods, suggesting results from both methods should be reported, particularly in the responsive range.

URLhttp://www.tandfonline.com/doi/abs/10.1080/00103624.2017.1411936
DOI10.1080/00103624.2017.1411936
Short TitleCommunications in Soil Science and Plant Analysis
Refereed DesignationRefereed
Status: 
Published
Attributable Grant: 
BREE
Grant Year: 
Year2
Acknowledged VT EPSCoR: 
Ack-No