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

This Article Figures Only Full Text 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 Google Scholar Articles by Zvomuya, F. Articles by Willms, W. D. PubMed Articles by Zvomuya, F. Articles by Willms, W. D. Agricola Articles by Zvomuya, F. Articles by Willms, W. D. Related Collections Soil Physics

SOIL PHYSICS

Surface Albedo and Soil Heat Flux Changes Following Drilling Mud Application to a Semiarid, Mixed-Grass Prairie

Agriculture and Agri-Food Canada, Lethbridge Research Centre, 5403 1st Ave. S., Lethbridge, AB, Canada T1J 4B1

^* Corresponding author (zvomuyaf{at}cc.umanitoba.ca).

Drilling mud systems are used by the petroleum industry to facilitate and expedite the drilling of oil and natural gas wells. In western Canada, spent water-based muds (WBM) are often applied to cropland and native prairie at low application rates as a disposal option. We speculate that application of drilling waste on native prairie in semiarid climates will alter the soil surface energy balance and adversely affect soil biophysical processes and subsequently ecosystem productivity. This study was initiated to examine the effect of application rate (0, 40, and 80 m³ ha^–1) of summer-applied WBM on surface albedo (), soil temperature, and soil heat flux at the 0.05-m depth (G_0.05) and at the surface (G) over 42 d following application. Our results provide evidence of a significant alteration of these micrometeorological parameters with WBM application. Surface albedo decreased by 15% (relative to the control) with the application of 40 m³ ha^–1 mud and by an additional 3% when this mud rate was doubled. The lower meant that a greater proportion of incoming shortwave solar radiation (R_si) was available for partitioning into components of the surface energy balance, including G. This coincides with observed increases in G_0.05, G, and soil temperature at the 0.025-m depth, with higher WBM. By modifying heat flow and temperature in the root zone, WBM application may alter critical ecosystem biophysical and physiological processes, with important implications for overall biological productivity. The direction and magnitude of such changes, in conjunction with all the other ecological effects of WBM, will ultimately define the sustainability of the practice in this fragile ecosystem.

Abbreviations: DOY, day of year • LWD, landspraying while drilling • SZA, solar zenith angle • TOC, total organic C • WBM, water-based mud