Daddow, Richard L.; Warrington, Gordon E. 1983. Growth-limiting soil bulk densities as influenced by soil texture. Watershed Systems Development Group Report: WSDG-TN-00005. Fort Collins, CO: U.S. Department of Agriculture, Forest Service.
An important forest management concern is the possibility of reduced vegetative productivity due to soil compaction. Various research studies have shown the detrimental effects of soil compaction on the establishment and growth of forest and range plants (Lull 1959, Foil and Ralston 1967, Hatchell et al. 1970, Wilshire et al. 1978, Froehlich 1979, Greacen and Sands 1980, Wert and Thomas 1981). The effects of soil compaction on plant growth are a complex interaction between many soil and plant properties, but for many situations there appears to be an upper limit or threshold soil bulk density value where resistance to root penetration is so high that plant root growth is essentially stopped (O'Connell 1975). Restricted root penetration and elongation reduces the volume of soil that can be exploited by a plant for essential nutrients and water, which can cause a reduction in total growth. This threshold bulk density will be referred to as "growth-limiting" bulk density (GLBD).
GLBD is influenced by many soil properties but for most cases, soil texture appears to be the most important property determining the GLBD of a soil (Veihmeyer and Hendrickson 1948, Schuurman 1965, O'Connell 1975). The main reason why soil texture strongly influences GLBD is its effect on soil pore size and mechanical resistance.
The purpose of this paper is to (1) discuss the relationship between soil texture and GLBD, (2) provide forest soil scientists with a tool for estimating the GLBD of many different kinds of soils, and (3) illustrate how GLBD may be used to guide management practices so that vegetative growth is not significantly reduced by soil compaction.