Pedosphere 21(2): 139--145, 2011
ISSN 1002-0160/CN 32-1315/P
©2011 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Free Cu2+ ions, Cu fractionation and microbial parameters in soils from apple orchards following long-term application of copper fungicides |
ZHOU Dong-Mei1 , WANG Quan-Ying1,2 and CANG Long1 |
1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)
2 Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012 (China) |
| ABSTRACT |
| Soil samples were collected from apple orchards 5,15,20,30,and 45 years old,and one adjacent forest soil was used as reference to investigate the free Cu2+ ion activity in soil solution and the soil Cu fractionation in the solid phase following long-term application of copper fungicide,Bordeaux mixture,in apple orchards and to investigate the relationships among soil free Cu2+ ions,Cu fractionation and soil microbial parameters.The total Cu concentration in the orchard soils varied from21.8 to 141 mg kg-1,increasing with the orchard age,and the value for the reference soil was 12.5 mg kg-1.The free Cu2+ ion concentrations in the soil solutions extracted by 0.01 mol L-1 KNO3 ranged from 3.13×10-8 (reference) to 4.08×10-6 mol L-1 (45 years-old orchard).The concentration of Cu complexed in the fulvic fraction increased with orchard age from 5.16 to 52.5 mg kg-1.This was also the case for other soil Cu fractions except the residual one.The residual soil Cu remained practically constant,ranging from 4.28 to 5.66 mg kg-1,suggesting that anthropogenic soil Cu mainly existed in the more labile active fractions.Regression analyses revealed that both the free Cu2+ ions in the soil solution and the humic acid-complexed Cu fraction in the solid phase were strongly related with soil microbial parameters. |
| Key Words: free metal activity, fulvic acid-complexed Cu, humic acid-complexed Cu, orchard soil, residual Cu |
| Citation: Zhou, D. M., Wang, Q. Y. and Cang, L. 2011. Free Cu2+ ions, Cu fractionation and microbial parameters in soils from apple orchards following long-term application of copper fungicides. Pedosphere. 21(2): 139-145. |
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