fect of paper mill sludge compost on aluminum pollution in acid soil

The aluminum pollution in red soil and plant when paper mill sludge compost(PMSC) was applied in a maize pot experiment was evaluated. The results showed that the active aluminum concentration in treatments added with PMSC was much higher than that of CK in the early stage of pot plant, and the active aluminum concentration increased with the increase of compost. But the former decreased sharply during planting, and were lower than that in the original red soil at the end of planting. During the whole period of pot plant, ttotal monomeric aluminum was the main existing form of active aluminum in soil. The aluminum concentrations in maize plant(leaves, stems and roots) were all lower than CK and the maize planted with PSMC grew better than CK, which indicated that PMSC was suitable to apply in red soil because it could improve soil nutrients and cause no aluminum pollution in soil-plant. The better ratio of PSMC to soil was 10%. The experimental results also showed that pH value, organic carbon(OC) concentration and effective phosphate concentration of red soil increased after addition of PSMC.