Effects of Compost on the Chemistry of an Urban Upper Piedmont South Carolina Soil

Composting is an effective method to improve the fertility of degraded soils. However, the potential beneficial effects of composting on the fertility of urban soils have not been reported. This study compared nutrients measured in compost and soil samples collected from a residential urban plot in Clemson, SC. The dominant soil type present was an eroded Cecil sandy loam (fine, kaolinitic, thermic, Typic Kanhapludults), and the collected samples represented the following treatments: compost, garden, front lawn, backyard lawn, and basement (nonvegetated control). Tissues of leaf detritus were also analyzed to establish the nutrient contribution from leaves to soil. Standard soil tests were conducted to characterize soil macronutrients, macrominerals, and micronutrients, as well as soil parameters such as pH and cation exchange capacity (CEC). Analysis of variance (ANOVA) was used to compare the treatment means for each soil parameter and nutrient measured. In all cases, the different treatments had significantly different levels of nutrients based on Fisher's least significant difference (LSD) (P<0.05). Our results show that composting can be a significant source for major soil nutrients and minerals in urban soils. Therefore, utilization of compost and leaf detritus should be beneficial for improving degraded soil in urban environments.