PHYSICAL CHARACTERISTICS OF A SANDY SOIL AMENDED WITH MUNICIPAL SOLID-WASTE COMPOST

The municipal solid waste stream going to landfills includes many organic fractions that can be applied to agricultural lands and reduce landfill loading. This study was conducted to determine the effects of incorporation of municipal solid waste compost (MSWC) in a sandy soil on dry bulk density and water holding capacity. In June 1992, MSWC was incorporated as a soil amendment to EauGallie fine sand (sandy, siliceous, hyperthermic Alfic haplaquod) at the Gulf Coast Research and Education Center in Bradenton, Florida. Rates of 0, 67 and 134 metric tons of MSWC ha-1 were applied to 12.5 m wide by 15.2 m long field plots with four replications of each application. Soil samples were taken from all field plots in July 1992 following incorporation and July 1993 following two cropping seasons for water retention and particle size analysis. Soil water retention characteristics were determined using a pressure plate system, and particle size distribution was measured with sieves. Dry bulk density decreased with MSWC rate each year. However, dry bulk densities of amended soils in 1993 were closer to control sample levels. While incorporation of MSWC increased the water holding capacity of the soil, the shape of the pressure potential water content curve did not appear to change and plant available water released between any two given pressure points did not change. Variation among 1992 water content data points increased with increasing levels of MSWC. However, July 1993 data were less variable, indicating a more uniform distribution of MSWC in the soil.