Translator Disclaimer
1 May 2011 Spatial and seasonal variability of phosphorus risk indexes in cultivated organic soils
Julie É Guérin, Léon-Étienne Parent, Bing C. Si
Author Affiliations +
Abstract

Guérin, J. É., Parent, L.-É. and Si, B. C. 2011. Spatial and seasonal variability of phosphorus risk indexes in cultivated organic soils. Can. J. Soil Sci. 91: 291-302. Many reports have attributed phosphorus (P) leaching from cultivated organic soils and the eutrophication of adjacent surface waters to P fertilization exceeding the P sorption capacity of the soil. The index of phosphorus saturation (IPS) using the Mehlich III method (M-III) has been proposed to define an agri-environmental threshold of P saturation in cultivated organic soils. The spatial and temporal variability of IPSM-III must be documented and related to the risk of P pollution to recommend more efficient fertilization practices. The objective of this research was to measure spatial and seasonal variation patterns of P in cultivated organic soils and to evaluate the losses of soil test extractable P between autumn and the following spring. Composite soil samples were taken on a 25-× 25-m grid within 7-ha areas in three representative types of cultivated organic soils of southwestern Quebec in fall 2006 and spring 2007. Soil P, iron, and aluminum were extracted in duplicate using the M-III and the acid ammonium oxalate methods (OX). The spatial analysis of organic soils showed that the PM-III and the IPSM-III were spatially autocorrelated and that the experimental semivariograms can be described by linear to sill or spherical models with ranges of 68 to 168 m. There was a high seasonal variability among the PM-III and the IPSM-III values. The IPSM-III values were generally higher than the environmental threshold of 0.05 across sites and sampling periods. Losses of M-III and OX extractable P averaged 41 kg PM-III ha-1 and 84 kg POX ha-1, respectively, between fall and the following spring, suggesting substantial contribution of cultivated organic soils to the pollution of downstream surface waters.

Julie É Guérin, Léon-Étienne Parent, and Bing C. Si "Spatial and seasonal variability of phosphorus risk indexes in cultivated organic soils," Canadian Journal of Soil Science 91(2), 291-302, (1 May 2011). https://doi.org/10.1139/CJSS10089
Received: 4 August 2010; Accepted: 1 February 2011; Published: 1 May 2011
JOURNAL ARTICLE
12 PAGES


Share
SHARE
KEYWORDS
Eutrophication
Eutrophication
index of phosphorus saturation
indice de saturation en phosphore
Mehlich III method
méthode Mehlich III
organic soil
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top