Composted MSW effects on soil properties and native vegetation in a degraded semiarid shrubland

Three rates of dried composted MSW (40, 80 and 120 Mg ha(-1)) were surface applied to a degraded semiarid shrubland site near Madrid in central Spain. Various soil and plant parameters were determined one year after its appli cation. MSW amendment had an effect on soil chemistry and nutrient levels. Available P and K, concentration of N-NO3 and EC. increased significantly a fter the MSW application. The concentration of total soil heavy metals, Zn, Pb, Cd, Ni, Cr and Cu rose with the application of MSW as compared with th e control plot, but these increases were only significant in total Zn, Pb a nd Cu. Zn and Cu amounts of DTPA-extractable soil were also significantly h igher in the amended soil. Total plant cover increased significantly in the plots treated with low and intermediate MSW rates. Total biomass productio n increased as compost rates were added but this rise is not proportional t o the amount of MSW added. The degraded soil used in this study may require MSW rates up to 80 Mg ha(-1) to improve soil chemical properties as well a s to produce minimal changes in the native vegetation.