Determining saturated hydraulic conductivity of a repacked loam soil by the simplified falling-head technique: Impact of sieving duration and scraping of exposed surfaces

Abstract

Many methods are used in laboratory for packing sieved soil. Determination of soil properties is expected to vary with the applied packing method. The objective of this investigation was to test the impact of initial soil sieving duration and scraping of exposed soil surfaces on saturated hydraulic conductivity, Ks, of an initially air-dry loam soil determined by the simplified falling-head technique. Two sieving durations (5 and 30 min) were considered. A brush was used to scrape exposed surfaces for half of the tested soil columns. A long sieving yielded a finer soil than a short sieving and 9-22% smaller values of Ks. Scraping the exposed soil surfaces yielded 4-17% smaller Ks values than those obtained on the not scraped columns. None of the observed differences was statistically significant. Therefore, sieving duration and treatment of the exposed soil surfaces were minor factors influencing determination of Ks. Reaching general conclusions about sieving duration and scraping effects requires testing these factors with other soils, initial soil water conditions and Ks measurement techniques.