Campus Units

Agronomy

Document Type

Article

Publication Version

Published Version

Publication Date

1997

Journal or Book Title

Soil Science Society of America Journal

Volume

61

Issue

4

First Page

1030

Last Page

1036

DOI

10.2136/sssaj1997.03615995006100040006x

Abstract

Determining the preferential flow characteristics of a soil is important because agrichemicals can contaminate groundwater via preferential flow pathways. A model that predicts solute transport due to preferential flow is the mobile-immobile solute transport model, which partitions the total water content (θ, m3 m−3) into a mobile fraction (θm) and an immobile fraction (θim). Recently, an in situ method was proposed for determining the mobile-immobile model parameters of θim and mass exchange coefficient (α) between the fractions by using a tension infiltrometer to apply a series of four fluorobenzoate tracers. The objective of this study was to test the in situ technique at 47 sites along a transect in a ridge-till corn (Zea mays L.) field of Nicollet soil (fine-loamy, mixed, mesic Aquic Hapludoll). The immobile fraction (θim /θ) ranged from 0.394 to 0.952 with a median of 0.622. The mass exchange coefficient ranged from 0.000237 to 0.00481 min−1 with a median of 0.00123 min−1. These values are similar in magnitude and range to values reported by other investigators, and they follow the same relationships. The values of θim/θ and α along the transect indicated no obvious spatial trends or spatial correlations. Significant linear correlations did exist between α and soil water flux, α and θim, and θ and θim.

Comments

This article is published as Casey, F. X. M., R. Horton, S. D. Logsdon, and D. B. Jaynes. "Immobile water content and mass exchange coefficient of a field soil." Soil Science Society of America Journal 61, no. 4 (1997): 1030-1036. Doi: 10.2136/sssaj1997.03615995006100040006x

Rights

Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. Content of this document is not copyrighted.

Language

en

File Format

application/pdf

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