| For many years, environmentalists have extolled the benefits of compost, a mixture of organic residues that have been piled, moistened and allowed to undergo biological decomposition. Researchers have evaluated various organic composts as a natural alternative to traditional soil treatments. Because the composition of compost is variable, it is difficult to characterize the benefits of a specific compost based on previous studies. Numerous investigations have furnished evidence that compost does provide quantifiable beneficial effects on a wide range of ornamental plant materials. However, a comparatively small amount of information has been assembled on how the incorporation of compost affects the physical properties of urban soils.; One key product derived from the decomposition of compost is humus, which has been shown to directly affect several physical properties in soils. Improved soil aggregation, increased water infiltration and percolation rates, and a reduction of certain detrimental soil properties can all be influenced by variable levels of soil humus.; Lawns of Dallas (LOD), the corporate sponsor of this study, collects hundreds of cubic yards of organic waste material annually. Leaves, grass clippings, wood chips, and other debris are collected and piled into large windrows. Following processing and decomposition, the final product is reintroduced into flower and shrub beds as a soil amendment. Lawns of Dallas has maintained detailed records and photographs of its compost being incorporated into soils for many years. Careful examination of these sites provided information on the residual effects of LOD compost.; A wide variety of soils occur in the Dallas metropolitan area. The majority of these soils have been altered from their native state due to excavation, tilling, and compaction. Some of the soils have high shrink-swell (vertic) properties. If the application of compost reduces the expression of vertic properties, the economic gains from its use could be substantial.; This dissertation quantified the effects of the application of LOD compost on (a) the coefficient of linear extensibility, (b) infiltration rate, (c) water content, and (d) overall turf quality, and (e) evaluated the longevity of the effects. |
