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Diffusive Gradients in Thin Films as a Reference Method for Assessing Soil Phosphorus by Visual and Near‐Infrared Spectroscopy
Author(s) -
Maarschalkerweerd Marie,
Gao Songjuan,
Bai Jinshun,
Husted Søren,
Cao Weidong,
Holm Peter E.
Publication year - 2016
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/jeq2016.05.0195
Subject(s) - diffusive gradients in thin films , soil water , environmental science , leaching (pedology) , phosphorus , surface runoff , soil test , environmental chemistry , chemistry , soil science , agronomy , ecology , biology , organic chemistry
Phosphorus (P) deficiency is a severe challenge in many agricultural areas around the globe, while at the same time, aquatic environments are threatened by leaching and runoff of excess P in other areas. Accurate, cheap, and rapid assessment of crop P needs and risk of P loss is therefore necessary to optimize the use of P fertilizer worldwide. The purpose of this study was to develop a method to predict soil P concentrations by visual and near‐infrared spectroscopy using reference P concentrations determined by diffusive gradients in thin films (DGT); Olsen P results were included for comparison. The study was conducted on paddy soils from six main rice‐producing ( Oryza sativa L.) provinces in southern China. Using DGT P as a reference resulted in a better visual and near‐infrared calibration to predict soil P concentrations, as compared with using Olsen P. Core Ideas Determining soil P by Vis‐NIR spectroscopy is possible. Using DGT P as the reference method is superior to using Olsen P. Less variation in soil properties is likely to increase model quality. Soil organic matter, improving plant P availability, affects DGT P more than Olsen P.