Pedosphere 10(1): 1--9, 2000
ISSN 1002-0160/CN 32-1315/P
©2000 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Modelling of cadmium transport in soil-crop system |
| WEI Shi-Qiang1 and N. JARVIS2 |
1 College of Resources and Environment, Southwest Agricultural University, Chongqing 400716 (China)
2 Department of Soil Science, Swedish University of Agricultural Sciences, Uppsala, Box 7014, 75007 (Sweden) |
| ABSTRACT |
| A model for simulating cadmium transport in a soil-plant system was built using a commercial simulating program named Powersim on the basis of input-output processes happening in the soil-plant system. Convective and dispersive transport processes of cadmium in soil profile are embedded. Simulations on a daily base have been done up to a total simulating time of 250 years. Results show that applications of sewage sludge and fertilizer at the simulated rates would only cause slight cadmium accumulations in each layer of the soil, and cadmium accumulation would be levelling off, reaching an equilibrium concentrations layer by layer downward after certain time. The time scale to reach an equilibrium concentration varies from 10 years for the top three layers to over 250 years for the bottom layers. Plant cadmium uptake would increase from 52 ug m-2 under initial soil cadmium concentrations to 65 ug m-2 under equilibrium soil cadmium concentrations, which would not exceed the maximum allowable cadmium concentration in wheat grains. Main parameters which influence cadmium accumulation and transport in soil are total cadmium input, rainfall, evaporation, plant uptake and soil properties. |
| Key Words: accumulation, cadmium, modelling, transport, uptake |
| Citation: Wei, S. Q. and Jarvis, N. 2000. Modelling of cadmium transport in soil-crop system. Pedosphere. 10(1): 1-9. |
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