SOIL SURFACE HYDRAULIC AND CHEMICAL TRANSPORT PROPERTIES

Authors: GAUR, ANJU - IOWA STATE UNIVERSITY; HEITMAN, JOSH - IOWA STATE UNIVERSITY; HORTON, ROBERT - IOWA STATE UNIVERSITY; Jaynes, Dan

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/4/2004
Publication Date: 11/4/2004
Citation: Gaur, A., Heitman, J., Horton, R., Jaynes, D.B. 2004. Soil Surface Hydraulic and Chemical Transport Properties [CD-ROM]. ASA-CSSA-SSSA Annual Meeting Abstracts. Madison, Wisconsin.

Interpretive Summary:

Technical Abstract: Knowledge of hydraulic and solute transport properties is required in order to evaluate the risks of agricultural chemicals contaminating groundwater under a wide variety of crop and soil management practices. The objective of our study was to determine the surface hydraulic and solute transport properties and to evaluate the effects of soil structural characteristics for different soil and tillage management zones. A dripper-time domain reflectometery (TDR) field setup was used to determine the surface hydraulic and chemical transport properties. The hydraulic properties (saturated hydraulic conductivity and macroscopic capillary length) were determined by measuring the resultant steady-state flux densities for three dripper discharge rates from the drippers. A salt solution was applied to each TDR probe location and the transient bulk electrical conductivity of the surface soil at steady-state flow of solutions. The chemical resident concentrations measured by TDR were used to determine the dispersivity and mobile-immobile water fraction. The soil structural characteristics included measurement of bulk density, cracks, and other morphological features. We evaluated the effect of soil structural characteristics on saturated hydraulic conductivity, dispersivity, and mobile-immobile water content in traffic and non-traffic interrows under no-till and till managements.