Laboratory-Scale Study on the Effects of Freezing in Soils when Subjected to Different Moisture Content

Abstract

This study was undertaken to investigate how soil characteristics and moisture content impact the freezing process in soils that are common in Georgia, United States. Three soil types (sand, loam, clay loam) with a water content of 30% or 40% field capacity were subjected to temperatures of −1.0 °C, −1.5 °C and −2.0 °C, respectively, in a freezing chamber. The three soil types revealed unique freezing profiles at both 30% and 40% field capacity. In general, all soil types at 40% field capacity remained at higher temperatures for longer periods of time compared to the same soil type at 30% field capacity. The loam soil at 40% WHC (water holding capacity) took the longest time to reach all four threshold temperatures. Both the soil texture and amount of water available for freezing affected the time each soil and water combination took to reach the threshold temperatures. These results have practical implications for the ornamental landscape industry and gardeners in subtropical climates where annual flowers are commonly grown in winter color beds. Since subfreezing soil temperatures are not as common in subtropical areas as they are in more northern climates, especially in recent decades, it would be worthwhile to examine the impact of additional factors such as organic content and nutrition on freezing processes in subtropical soils.