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Submitted to: Agronomy Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 11/8/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The movement of nutrients and other chemicals in the soil profile before, during, and after a winter season of freeze/thaw cycles is of considerable economic and environmental concern. Twelve soil columns 1.2 m long by 0.13 m inside diameter were packed with Webster silty clay loam top soil to bulk densities ranging from 1.0 to 1.4 and at initial water contents ranging from 0.16 to 0.34 kg/kg. Bromide was placed in the 0.5 to 0.15 m soil layers to simulate a fertilizer application. Groups of four soil columns were placed in a special freezing chamber to freeze the soil from the top to a depth of approximately 0.5 m. Eight of the columns went through one freeze/thaw cycle while the final four columns were subjected to four freeze/thaw cycles. Bromide breakthrough curves were obtained from each of the soil columns after the final thaw. Bulk density and initial water content significantly affected the flow rates and the time to peak bromide concentration in the outflow. While not significant in the overall experiment, there were indications that freezing and thawing may enhance the development of preferential flow paths through the part of the soil profile that had been frozen and thereby increase flow rates. More studies are needed to determine how such changes in flow patterns might affect leaching losses. |
