Production of composts from municipal solid wastes (MSW) and their application to sandy soils could resolve two great problems: a reasonable management of municipal solid wastes and amending of low fertility soils. In this paper the dose dependent effects of two MSW composts on the physical and physico-chemical properties of sandy soils are reported. Two different composts were produced in composting plants in Katowice (an industrial region) and Zywiec (a rural region). Composts were applied in doses of 30, 60 and 120 t.ha(-1). Plots without fertilization as well as plots fertilized in each year with mineral NPK were used as control. During the first year of the experiment, decreasing bulk density and increasing total porosity have been statistically proven; applying 120 t MSW compost increased total porosity from 0.396 (control) up to 0,480 m(3) m(-3). An application of compost resulted in an increase in the field water retention capacity, while the amount of water available for plants in range of pF 2.0 - 2.95 was not affected. Changes of soil physical properties were observed in plots where the largest dose of MSW compost was applied. The improvement of soil physical properties was observed only in the first year of the experiment, with no significant changes during the following seasons. In regard to the physico-chemical properties, the cation exchange capacity and the base saturation of the sorption complex of the soil increased. This effect was observed even in the third year of the experiment, but only on plots fertilized with the largest dose of composts. The increase in the content of plant-available P, K, and Mg in soil was significant in all treatments during a 3-year experiment. The experiment indicated that an application of MSW composts improves fertility of sandy soils, while extent and stability of changes depends on the amount and quality of organic matter applied with the compost.
