| The remediation effects of lime, rice straw, pig manure, sheep manure, peat, lime + rice straw, lime + pig manure, lime + sheep manure, lime + peat for a cadmium, lead and zinc contaminated soil were studied by soil culture experiments with rice and water spinach. The main results were as follows:1. The application of lime increased the pH and CEC of the soil while the application of rice straw or peat increased soil organic matter content and CEC. The application of pig manure, sheep manure and the combined application of all the organic materials with lime increased pH, organic matter content and CEC. The change of the soil properties influenced the availability of Cd, Pb and Zn in the soil. The available Cd, Pb and Zn had significant and negative correlation with soil pH. Lime + pig manure showed the strongest inhibitory effects on the availability of Cd, Pb and Zn, with the available Cd, Pb and Zn being reduced by 81.04%, 47.52% and 36.95%, respectively for the rice-planting soils, and by 72.22%, 74.27% and 75.15%, respectively for the vegetable-planting soils.2. The combined application of most of the organic materials with lime had better inhibitory effects on the transfer of Cd from the soil to rice grain as revealed by the BCF (Cd in the unpolished grains/soil available Cd) than the individual application of the organic materials. The concentration of Cd in the unpolished rice grains of the lime + pig manure treatment was decreased by 85.71% as compared with that of the control, being the lowest among all the treatments. The individual application of the organic materials showed better inhibitory effects on the transfer of Pb from the soil to rice grain as revealed by the BCF(Pb in the unpolished grains/soil available Pb) than the combined applications. As compared with that of the control, the concentration of Pb in the unpolished rice grains of lime and straw treatment was decreased by 54.37% and 53.15%, respectively, being the lowest among all the treatments. As for the inhibitory effects on the transfer of soil Zn from the soil to rice grain, the combined application of rice straw + lime was better than the individual application of rice straw while the individual application of pig manure was better than lime + pig manure. The other combined application of lime with organic materials had no significant differences with the individual applications. The Zn concentration of the unpolished rice grains of the individual application of pig manure was the lowest among all the treatments, being 32.10% lower than that of the control.3. The individual application of most of the organic materials had better inhibitory effects on the transfer of Cd from the soil to the shoots of water spinach as revealed by the BCF (Cd in the unpolished grains/soil available Cd) than the combined application of the organic materials with lime. The Cd concentration in the shoot of water spinach of pig manure treatment was 56.35% lower than that of the control, being the lowest among all the treatments. The combined application of lime + organic materials inhibited better the transfer of Pb from the soil to the shoots of water spinach than that of the individual applications. The Pb concentration of the shoot of water spinach from lime + pig manure treatment was reduced by 70.90% as compared with that of the control, being the lowest among all the treatments. The combined application of lime + organic materials showed better inhibitory effects on the transfer of Zn from the soil to the shoots of water spinach than that of the individual application. The treatments of sheep manure, lime + pig manure and pig manure inhibited well the transfer of soil Zn to the shoot of water spinach, with the Zn concentrations of the shoots of the three treatments being 71.62%,70.75% and 69.98% lower than the control.4. The available Cd of the soil treated with lime + sheep manure did not change apparently, while those of other treatments increased in varying degrees from rice planting to vegetable planting. The available Pb of most of the soils increased whereas those of the soils treated with pig manure, lime + rice straw, and lime + pig manure were still lower than those of the control. The available Zn of the soils treated with lime + rice straw and lime + pig manure did not change significantly whereas those of the soils treated with pig manure, lime + pig manure and lime + sheep manure decreased. The soil Zn of all the other treatments was more or less activated.
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