In:
Vadose Zone Journal, Wiley, Vol. 2, No. 4 ( 2003-11), p. 618-626
Abstract:
The saturated hydraulic conductivity ( K s ) is an essential parameter for modeling water and chemical transport in the vadose zone. Since in situ measurements of K s are complex and time‐consuming, indirect methods that are dependable, fast, and inexpensive with regard to assessing magnitude and spatial variability in K s at the field scale are needed. In situ measurements of air permeability ( k a,in situ ) may fulfill these criteria. In this study, a portable insertion‐type air permeameter was used to measure k a,in situ in the Ap and B horizons at five agricultural field sites in Denmark with soil types ranging from sand to sandy loam. Around 100 k a,in situ measurements were performed within 2 d at each field site. The data showed spatial correlation in k a,in situ at three out of five sites, with correlation distances between 30 and 〉 120 m. On the basis of additional laboratory measurements on large, undisturbed soil samples (6280 cm 3 ), a log‐log linear relationship between air permeability ( k a ) measured at the actual soil‐water content (close to field capacity) and K s was found. The K s – k a relation was in agreement with an earlier predictive relationship based on undisturbed 100‐cm 3 samples from nine other field sites. Using pedotransfer functions for K s based only on soil texture yielded an unrealistic narrow range in predicted K s values whereas pedotransfer functions based on k a,in situ yielded a more realistic prediction range. Measurements of k a,in situ constitute a promising indirect method for assessing spatial variability in K s at the field scale.
Type of Medium:
Online Resource
ISSN:
1539-1663
,
1539-1663
DOI:
10.2136/vzj2003.6180
Language:
English
Publisher:
Wiley
Publication Date:
2003
detail.hit.zdb_id:
2088189-7
