HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mallawatantri, A. P. Articles by Mulla, D. J. Search for Related Content PubMed Articles by Mallawatantri, A. P. Articles by Mulla, D. J. Agricola Articles by Mallawatantri, A. P. Articles by Mulla, D. J.

Uncertainties in Leaching Risk Assessments Due to Field Averaged Transfer Function Parameters

Department of Soil, Water, and Climate, Univ. of Minnesota, St. Paul, MN 55108-6028

*Corresponding author (dmulla{at}soils.umn.edu).

ABSTRACT

The transfer function model is widely used to estimate solute transport patterns at the field scale. Leaching risk assessments with the transfer function model may be influenced by spatial variability in the net applied water (NAW) distribution, but few researchers have investigated this possibility. The objective of this study was to evaluate the impact of spatial variability in the NAW distribution on leaching risk assessment and identification of leaching risk categories at the field scale. Bromide concentration profiles, irrigation depths, bulk densities, and soil moisture contents were measured in 40 plots across a 57-ha potato (Solanum tuberosum L.) farm, along with field-scale evapotranspiration estimates, to estimate solute transport parameters. Values for field- and plot-scale means and standard deviations for the NAW distribution were estimated using the stochastic convective lognormal transfer function (CLT) model. The probability of NO^–₃ leaching below a depth of 2 m was then estimated using field-averaged versus plot-scale estimates for the mean and standard deviation of the NAW distribution. For 30-cm NAW, NO^–₃ leaching risks estimated with the CLT model and plot-scale means and standard deviations were very high in 0.4 ha of the field, high in 1.8 ha, moderate in 8.7 ha, low in 23.0 ha, and none in 23.1 ha. In contrast, when field-scale average estimates of NAW were used, there was a low risk of NO^–₃ leaching for the entire field. Thus, when estimating leaching risks using the CLT, information about spatial variability of the NAW distribution is important.

Received for publication March 5, 1995.

This article has been cited by other articles:

				L. Ren, J. Ma, and R. Zhang Estimating the Influence of Nitrogen Transformations on Nitrate Leaching in Soils Soil Sci. Soc. Am. J., August 9, 2007; 71(5): 1460 - 1468. [Abstract] [Full Text] [PDF]

				E. Perfect and J. Caron Spectral Analysis of Tillage-Induced Differences in Soil Spatial Variability Soil Sci. Soc. Am. J., September 1, 2002; 66(5): 1587 - 1595. [Abstract] [Full Text] [PDF]