HR: 0800h
AN: H21B-1346    [Abstracts]
TI: Measuring Hydraulic Properties of Soil-Foundry Sand Mixtures
AU: * Shouse, P J
EM: pshouse@ussl.ars.usda.gov
AF: George E. Brown Jr. Salinity Laboratory, 450 W. Big Springs Rd., Riverside, CA 92507 United States
AU: Dungan, R S
EM: RDUNGAN@anri.barc.usda.gov
AF: Environmental Management and Byproduct Utilization Laboratory , 10300 Baltimore Ave Bldg 306, Room 113 , Beltsville, MD 20705 United States
AU: Dees, N
EM: NDEES@anri.barc.usda.gov
AF: Environmental Management and Byproduct Utilization Laboratory , 10300 Baltimore Ave Bldg 306, Room 113 , Beltsville, MD 20705 United States
AU: Fargerlund, J
EM: jfargerlund@ussl.ars.usda.gov
AF: George E. Brown Jr. Salinity Laboratory, 450 W. Big Springs Rd., Riverside, CA 92507 United States
AB: The foundry industry produces clay coated sand particles that have potential to affect soil water retention and conductivity if mixed with soils at the proper ratio. The purpose of our study was to determine the effects of mixing foundry sand on increasing the saturated hydraulic conductivity of slowly permeable soils. Our methods included mixing Walla-Walla silt loam soil with increasing volumes of foundry sand from 0% to 100%. We then used several packing methods to determine the optimum bulk density for our automated retention and outflow experiments. To increase the range of the retention function, we also measured soil water retention using pressure plates at pressures between 1000 and 15000 cm pressure head. We measured saturated hydraulic conductivity using the constant head method and a single blind approach (the Ksat was measured in two labs, one had knowledge of the mixtures and one had no knowledge of the mixtures). The single blind approach was used to reduce the chance of bias in measuring Ksat and water retention. Our results for the saturated hydraulic conductivity did indicate that additions of foundry sand had a limited effect on Ksat until a critical level of sand was added to the mixture. The retention function was similarly affected by increasing volumes of foundry sand. The rankings of the Ksat measurements between the labs was constant, but the values obtained did differ (some significantly). For the Walla-Walla soil, additions of foundry sands exceeding 40% were needed to affect the measured Ksat and retention function. At these large volumes of foundry sands, it may be more appropriate to use the sands for new installations of turf grass such as athletic fields, and/or golf greens. We are continuing to study the characteristics of different foundry sands and quantifying their effects on the hydraulic properties of clay soils.
DE: 1832 Groundwater transport
DE: 1842 Irrigation
DE: 1866 Soil moisture
DE: 1875 Vadose zone
DE: 1894 Instruments and techniques: modeling
SC: Hydrology [H]
MN: Fall Meeting 2005