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Taking rice variety Shennong 265 as test material, a hydroponic experiment was conducted to investigate the effects of Fe (0, 0. 1, 0. 25 and 0. 5 mmol Fe2+·L-1) and Cd (0, 0. 1 and 1. 0 umol Cd2+ ·L-1 ) on the lipid peroxidation and antioxidative enzyme activities of rice plant. When the Fe was supplied alone, the shoot and root dry mass decreased significantly, but this phe-nomenon would not occur when the Cd was applied simultaneously. Applying Cd alone decreased the root malondialdehyde (MDA) and soluble protein contents, but applying Fe simultaneously alleviated the negative effects of Cd. Applying Fe decreased the Cd concentrations in shoots and roots, whereas applying Cd decreased the shoot and root Fe concentrations, indicating an obvious antagonistic interaction between Fe and Cd. The interaction of high concentration (1. 0 μmol·L-1) Cd with Fe increased the root MDA and soluble protein contents, and decreased the root superoxide dismutase (SOD) and catalase (CAT) activities. These results indicated that applying definite amount of exogenous Fe could decrease the Cd accumulation in rice under low Cd stress, whereas high Cd stress would decrease the Fe absorption by rice and induce the lipid peroxidation in rice plant. [ABSTRACT FROM AUTHOR]

In a pot experiment, hyperaccumulator Sedum plumbizincicola and low-cadmium accumulating Oryza sativa cultivar "Zhongxiang No. 1" were planted in rotation on a heavy metals-polluted soil, and calcium magnesium phosphate (Ca-P) and rock phosphate (P-R) were amended, aimed to study the effects of the rotation and phosphate amendment on the growth of the two plants and the zinc-and cadmium accumulation in their shoots. After the amendment of 50 g P-R∙kg-1, the Zn and Cd uptake by S. plumbizincicola was 11.5 mg∙pot-1 and 0∙79 mg∙pot-1, respectively, being significantly higher than that after the amendment of 4 g Ca-P∙kg-1. After the planting of S. plumbizincicola, the Zn and Cd concentrations in "Zhongxiang No. 1" increased, but the amendment of Ca-P decreased the accumulation of Zn and Cd in rice shoot significantly. The rotation with S. plumbizincicola and the amendment of Ca-P and P-R could immobilize the Zn and Cd in the contaminated soil as indicated by the quantitative change of NH4OAc-extractable Cd and Zn, and the efficiency of amendment with Ca-P was better than that of amendment with P-R. Field trial showed that amendment with Ca-P could not only increase the rice yield, but also reduce the Zn and Cd accumulation in rice shoot to a certain extent. [ABSTRACT FROM AUTHOR]

Taking rice variety Shennong 265 as test material, a hydroponic experiment was conducted to investigate the effects of Fe (0, 0.1, 0.25 and 0.5 mmol Fe2+ x L(-1)) and Cd (0, 0.1 and 1.0 umol Cd2+ x L(-1)) on the lipid peroxidation and antioxidative enzyme activities of rice plant. When the Fe was supplied alone, the shoot and root dry mass decreased significantly, but this phenomenon would not occur when the Cd was applied simultaneously. Applying Cd alone decreased the root malondialdehyde (MDA) and soluble protein contents, but applying Fe simultaneously alleviated the negative effects of Cd. Applying Fe decreased the Cd concentrations in shoots and roots, whereas applying Cd decreased the shoot and root Fe concentrations, indicating an obvious antagonistic interaction between Fe and Cd. The interaction of high concentration (1.0 micromol x L(-1)) Cd with Fe increased the root MDA and soluble protein contents, and decreased the root superoxide dismutase (SOD) and catalase (CAT) activities. These results indicated that applying definite amount of exogenous Fe could decrease the Cd accumulation in rice under low Cd stress, whereas high Cd stress would decrease the Fe absorption by rice and induce the lipid peroxidation in rice plant.

In a pot experiment, hyperaccumulator Sedum plumbizincicola and low-cadmium accumulating Oryza sativa cultivar "Zhongxiang No. 1" were planted in rotation on a heavy metals-polluted soil, and calcium magnesium phosphate (Ca-P) and rock phosphate (P-R) were amended, aimed to study the effects of the rotation and phosphate amendment on the growth of the two plants and the zinc- and cadmium accumulation in their shoots. After the amendment of 50 g P-R x kg(-1), the Zn and Cd uptake by S. plumbizincicola was 11.5 mg x pot(-1) and 0 x 79 mg x pot(-1), respectively, being significantly higher than that after the amendment of 4 g Ca-P x kg(-1). After the planting of S. plumbizincicola, the Zn and Cd concentrations in "Zhongxiang No. 1" increased, but the amendment of Ca-P decreased the accumulation of Zn and Cd in rice shoot significantly. The rotation with S. plumbizincicola and the amendment of Ca-P and P-R could immobilize the Zn and Cd in the contaminated soil as indicated by the quantitative change of NH4OAc-extractable Cd and Zn, and the efficiency of amendment with Ca-P was better than that of amendment with P-R. Field trial showed that amendment with Ca-P could not only increase the rice yield, but also reduce the Zn and Cd accumulation in rice shoot to a certain extent.

Thermophilic composting of pig manure was studied in an attempt to elaborate upon organic matter transformation during the process and provided parameters for product maturity using chemical method. The following parameters were measured in 11 samples during the 42 days of composting: organic matter, dissolved organic carbon (DOC), degradable organic matter and humic matter (HM). Organic matter decreased during composting process constantly; DOC concentration increased to maximum at 10 days and declined thereafter; degradable organic matter decreased whole composting, but they increased in start of high-temperature stage; The increasing level of HM at various stages of composting indicate the progression of humification; H/F provide information correlating to conventional chemical parameters (organic matter, DOC) of compost maturity. Moreover, H/F has correlating to degradable organic matter and HM.