Submitted to: Transactions of the ASAE
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/4/2003
Publication Date: 1/20/2004
Citation: Farahani, H., Buchleiter, G.W. 2004. Temporal stability of soil electrical conductivity in irrigated sandy soils. Transactions of the ASAE. V47(1): 79-90. Interpretive Summary: An EC mapping devise was used to map soil characteristics of three center-pivot fields in eastern Colorado from 1998 to 2002. Our objective was to determine the stability of EC maps over time. Results show that in the non-saline fields examined in this study, EC patterns, and not absolute EC values, remained largely unchanged between 1998 and 2002. The stability of EC patterns over time is attributed to its relationship with soil factors, such as clay, sand, and organic matter contents. Only significant land modifications (such as leveling) on the non-saline soils could alter soil stable properties and thus EC patterns. These findings justify EC measurements as an economical tool to create potential field areas that may benefit from varying management inputs and practices to be environmentally friendly.
Technical Abstract: The utility of bulk soil electrical conductivity (EC) remains elusive because of its complex interactions with soil properties. Nonetheless, a significant interest is emerging to utilize the spatial variability in EC to develop varying site-specific management. While the spatial variability of EC is of significant importance, understanding its temporal variability is equally important. That is particularly true if the same delineated EC zones are to be managed across years. We present multi-year measurements of EC from three fields in Colorado and quantify the temporal changes in EC. Both small- (a few days between measurements) and large-scale (a few years between measurements) temporal variability were found in the absolute magnitudes of EC. In these non-saline fields, the spatial patterns in EC were found to be highly stable over time, mainly because they reflect the stable soil properties.